Flowey

"In this world, it's kill or BE killed."

- Flowey's catchphrase. "Howdy! It's me, Flowey. Flowey the Flower! I owe you a huge thanks. You really did a number on that old fool. Without you, I never could have gotten past him. But now, with your help... He's DEAD. And I've got the human souls! Boy! I've been empty for so long... It feels great to have a soul inside me again. Mmmm, I can feel them wriggling... Awww, you're feeling left out, aren't you? Well, that's just perfect. After all, I only have six souls. I still need one more... Before I become GOD. And then, with my newfound powers... Monsters. Humans. Everyone. I'll show them all the REAL meaning of this world."

- Flowey before transforming into "Photoshop Flowey". "Let's destroy everything in this wretched world. Everyone, everything in these worthless memories... Let's turn 'em all to dust."

- Flowey on the Genocide Route.

Asriel Dreemurr, also known as Flowey, is the main antagonist of the 2015 RPG videogame Undertale, and the first character the protagonist meets after falling into the Underground. He appears as a small golden flower.

Past
Originally known as Asriel Dreemurr, he was born the child of Asgore and Toriel, the king and queen of the monsters. After a war against the humans forced all monsters underground, sealed away with a magical barrier, he lived his childhood separated from humans; however, when a child fell through the barrier, his family adopted them as their own. He soon became fast friends with the human child, and the two of them would do anything together.

Some time later, the child became deathly ill, and told Asriel of their desire to be returned to the surface and buried in their home village. Taking his sibling's soul, Asriel was able to breach the barrier and enter the human world, but when seen by the humans, he was accused of killing the child and was subsequently attacked. Despite having immense power from both a human and a monster's soul, he refused to fight back, and managed to return to the Underground before finally dying over a field of golden flowers. It later became clear that the child deliberately poisoned themself, as part of a plan devised with Asriel to gather six human souls, and wished to use their combined powers to kill the people in the village.

The royal scientist of the monsters, Alphys, was tasked with finding out a method of breaking the barrier without the use of a human's soul, and in doing so discovered the existence of a substance known as Determination, which kept human souls powerful even after death. After tests on giving Determination to monsters proved unsuccessful, she decided to test the substance on an object without a soul; one of the golden flowers Asriel died over. As a result, with his essence absorbed in the flower, he was reborn within it, with all his old memories, but without his soul.

Asriel attempted to live life with his father, and then with his separated mother, trying to regain his soul and emotions, but was ultimately unsuccessful. In the end, he ran away and attempted to kill himself, but when he changed his mind at the last minute, he found himself returned to an earlier point in time. He discovered that his Determination allowed him to undo and reset time itself, like saving and reloading a videogame, and began to experiment with his new power.

At first attempting to befriend all of the monsters around him, he soon grew bored with being able to predict people's reactions, and turned to violence instead. Now calling himself Flowey, he would kill every monster in the underground he could find, reset time, and repeat the process over again.

After a certain point, however, he found he could no longer alter time. The cause, he discovered, was due to a new child falling into the Underground, someone who looked just like his sibling from the past with powers of Determination able to override his own. Flowey then decided to use this child to his own advantage, leading them down a route where they would either die and return the power to him, or allow him to attain even greater power.

Undertale
Flowey introduces himself to the player at the start of the game, pretending to be a friendly figure introducing the mechanics of the game, but quickly reveals his true nature and tries to kill them immediately, only to be stopped by Toriel. After the child leaves the ruins and travels further into the Underground, he taunts the player based on whether or not they had killed anyone, before disappearing again. He follows the player through the game, staying just out of sight.

Neutral Run
In the Neutral ending, Flowey appears just before the player can kill Asgore, and deals the finishing blow himself, destroying both his own father and his soul. He then steals for himself the six human souls that Asgore had collected in hopes of destroying the barrier, and transforms into a horrific monster known as "Photoshop Flowey" with full control over time. Out of sheer pleasure, he traps the child in an endless battle, always bringing them to death or near death and then resetting time to do it all over again, while at the same time saving and loading moments in time when he can best hurt them. However, when the child calls out to the six human souls inside of him, they rebel against him and seal away his godlike powers. Completely helpless, he is left to the player's choice to either be killed or spared.

If killed, Flowey will acknowledge the player for following his philosphy ("In this world, its kill or be killed") and  killing him and turns into just a plain flower. He doesn't appear at the beginning if the player restarts, but still remains at the end. If spared, Flowey will be confused as to why the player decided to spare him and gives them several opportunities to make the killing blow. If you continue granting him mercy, he then threatens to kill the player's loved ones. If granted mercy enough times, Flowey will express his lack of understanding before running away.

Pacifist Run
This ending can only be achieved if a Neutral Route has been completed previously.

In the True Pacifist ending, Flowey organizes for every monster in the Underground to gather in Asgore's castle, and uses the opportunity to steal all of their souls at once. With so many combined souls, Flowey is able to finally take his true form as Asriel Dreemurr, and challenges the player head-on for the return of their souls and a "happy ending". As they battle, he expresses his true desire, to be able to play with his best friend and sibling for all eternity, no matter who is sacrificed in the process. He is ultimately defeated when the child reaches and frees the souls of the monsters trapped inside him, and finally frees his own soul. In a moment of pure lucidity, unaffected by emotions of rage and guilt, Asriel finally reaches peace with the child Frisk; he acknowledges that his sibling was not a good person, and releases the souls he had taken, after using his power to destroy the barrier and let monsters return to the surface.

In the epilogue, if the player/Chara/Frisk goes back to the first area of the game, they will find Asriel there, saying that he's decided to stay in the Underground, so that he will not harm anyone after he turns into Flowey again. If the player starts up the game after the True Pacifist ending, Flowey will appear to try to convince the player/Chara not to reset the game and everyone's happy ending, before saying that Chara must have "already heard him say it a hundred times". He says his final farewell to the player/Chara and leaves, referring to them with the First Human's name.

Genocide Run
In the Genocide route, Flowey is downgraded as secondary antagonist, the true main antagonist being Chara (Or possibly the player themself). If the player keeps murdering every monster on their way, Flowey finally realizes that the child was growing more evil than him, and that he too was in danger of dying. He quickly escapes to warn Asgore of the coming danger, while the child is distracted fighting Sans. When Asgore is ultimately brought near death, Flowey reappears and deals the finishing blow, claiming to have been on the child's side all along, crying and begging for forgiveness; thus, revealing his true identity as Asriel Dreemurr. However, his pleas are ignored as he is mercilessly killed by Chara, who slashes him repeatedly until nothing remains.

Personality
Initially, Flowey operates under a façade of friendliness and politeness. He often greets the protagonist with southern jargon, such as "Howdy!", calls himself "your best friend", and (like his father) appends polite words such as "gosh" and "golly" to the ends of his sentences. Whenever he drops this guise of friendliness, he often calls the protagonist an "idiot".

Flowey has a malevolent and cruel disposition, berating the protagonist for not following his "kill or be killed" philosophy. Despite this, he also criticizes the protagonist at the end of the Ruins if they killed any monster. He is a greedy, arrogant, egocentric, manipulative, devious, sly, and cunning planner, who is subtle if the circumstances require it. He retains his memories between SAVEs because he was once able to SAVE. He is also shown to be extremely solicitous, pusillanimous, diffident, and cowardly, as he kills his former father to appease the protagonist in a vain attempt to save his own life in the Genocide Route's conclusion.

Before his death, Asriel was a docile, unadventurous, and loving child. He cared for the First Human as a sibling, and he trusted them when they came up with a plan to escape the Underground that involved them consuming buttercups.

After Alphys resurrects Asriel without a SOUL as Flowey, he becomes incapable of feeling love. This makes him bored and resentful.

After temporarily regaining his compassion, he apologizes for his actions to Frisk and realizes the gravity of his actions as a flower.

Much like his father, he speaks using southern slang.

Appearance
Flowey usually appears as a sentient, grinning, golden flower, with a white androecium, six yellow petals, and a light green stem. Flowey can contort his face into a variety of expressions and mimic the faces and voices of other characters. He mimics Toriel and Asgore in some situations, as well as his old self at the end of the Genocide Route. He also mimics the protagonist's face before the Neutral Route's final battle.

After absorbing the human SOULs, Flowey transforms into a grotesque, flower-shaped hybrid of plant tissue, human organs, and machinery. Consisting entirely of rendered images, Photoshop Flowey is stylistically different from anything else in the game.

He has two sideways jaws, with tiny lumps on the end, and has two orifices that resemble nostrils, as well as an eye on each side with moving and pulsating irises, located within hollowed mouths. On top of his "face", he has a box TV that switches between a smiling face with huge teeth and sideways eyes that flash red and green. It will also flash vague, distorted black and white images of a terrified human face. The bottom of the mouth can overlap the TV's frame. He has metal, bumpy pipes that resemble petals and connect to the television and the jaws of his "face".

These jaws have floating eyes with moving and pulsating irises. He has many tubes that exit behind him, and big, thick vines that move away from him. He has cactus-like arms with red claws and dangling vines with leaves on them. His hands have the ability to retract and transform into Venus Flytraps.

Photoshop Flowey's new body resembles that of the DT Extraction Machine's structure, albeit now filled with teeth, gums, and eyeballs. Alphys used this machine to extract Determination from six previously captured human SOULs - the same SOULs that Photoshop Flowey uses to power himself.

Similar to Toriel and Asgore, Asriel has long ears, a snout, and visible fangs. In his initial form, he wears a green, long-sleeved shirt with yellow stripes and black pants, similar to the First Human's clothing. He also has a small wisp of fur on his head and lacks horns.

God of Hyperdeath
This form is named directly in the game, where the "Check" option labels Asriel as "the absolute GOD of Hyperdeath!" The sclerae of his eyes become black, his fangs become longer, and he has a pair of horns. He wears a long dark robe with white sleeves and the Delta Rune on the front, with a large collar and shoulder pads. This robe is similar to Toriel's. He also wears a locket similar to the Heart Locket.

Final Form
Asriel's body becomes more geometric, his horns are longer, and his teeth get sharper. He has a pair of wings that continuously change color, and his lower body becomes sharp and heart-shaped.

While this form is not directly named, it resembles the Delta Rune, which looks like the "Angel of Death" from the prophecy.

Quotes
"You IDIOTS. While you guys were having your little pow-wow... I took the human SOULS! And now, not only are THOSE under my power... But all of your FRIENDS' SOULS are gonna be mine, too! Hee hee hee. And you know what the best part is? It's all your fault. It's all because you MADE THEM love you. All the time you spent listening to them... Encouraging them... Caring about them... Without that, they wouldn't have come here. And now, with their souls and the humans' together... I will achieve my REAL FORM. Hee hee... Huh? WHY am I still doing this? Don't you get it? This is all just a GAME. If you leave the underground satisfied, you'll "win" the game. If you "win," you won't want to "play" with me anymore. And what would I do then? But this game between us will NEVER end. I'll hold victory in front of you, just within your reach... And then tear it away just before you grasp it. Over, and over, and over... Hee hee hee. Listen. If you DO defeat me, I'll give you your "happy ending." I'll bring your friends back. I'll destroy the barrier. Everyone will finally be satisfied. But that WON'T happen. You...! I'll keep you here no matter what!"

- Flowey when he attacks the cast and entangles them.

"ALL OF YOUR SOULS ARE MINE!!!"

- Flowey absorbing the monsters' SOULs.

"Finally. I was so tired of being a flower."

- Asriel regains his true form.

"Howdy! Chara, are you there? It's me, your best friend."

- Asriel calls out to his adoptive sibling.

"You know... I don't care about destroying this world anymore. After I defeat you and gain total control over the timeline... I just want to reset everything. All your progress... Everyone's memories. I'll bring them all back to zero! Then we can do everything ALL over again. And you know what the best part of all this is? You'll DO it. And then you'll lose to me again. And again. And again!!! Because you want a "happy ending." Because you "love your friends." Because you "never give up." Isn't that delicious? Your "determination." The power that let you get this far... It's gonna be your downfall! Now, ENOUGH messing around! It's time to purge this timeline once and for all!"

- Asriel reveals his true Intentions.

"... even after that attack, you're still standing in my way...? Wow... you really ARE something special. But don't get cocky. Up until now, I've only been using a fraction of my REAL power! Let's see what good your DETERMINATION is against THIS!!"

- Asriel after Frisk survives his Hyper Goner attack.

"Urah ha ha... Behold my TRUE power!"

- Asriel becomes the Angel of death.

"I can feel it... Every time you die, your grip on this world slips away. Every time you die, your friends forget you a little more. Your life will end here, in a world where no one remembers you..."

- Asriel telling Frisk that soon noone will remember them.

"Still you're hanging on...? That's fine. In a few moments, you'll forget everything, too. That attitude will serve you well in your next life!"

- Asriel tells Frisk that they will lose their memories once they die and are reborn.

"Ura ha ha... Still!? Come on... Show me what good your DETERMINATION is now!"

- Asriel surprised that Frisk is still alive.

"Huh? What are you doing...?"

- Asriel when Frisk saves someone.

"Wh... what did you do...? What's this feeling...? What's happening to me? No! NO! I don't need ANYONE! STOP IT! Get away from me! Do you hear me!? I'll tear you apart!"

- Asriel's response to Frisk trying to save him.

"... ... Chara ... Do you know why I'm doing this...? Why I keep fighting to keep you around...? I'm doing this... Because you're special, Chara. You're the only one that understands me. You're the only one who's any fun to play with anymore. ... No... That's not JUST it. I... I... I'm doing this because I care about you, Chara! I care about you more than anybody else! I'm not ready for this to end. I'm not ready for you to leave. I'm not ready to say goodbye to someone like you again... So, please... STOP doing this... AND JUST LET ME WIN!!! STOP IT! STOP IT NOW!!! ... Chara ... I'm so alone, Chara ... I'm so afraid, Chara ... Chara, I... I..."

- Asriel's last words as the Angel of Death.

"I'm so sorry. I always was a crybaby, wasn't I, Chara ... ... I know. You're not actually Chara, are you? Chara's been gone for a long time. ... Um... what... What IS your name? ... "Frisk?" That's... A nice name. ... Frisk... I haven't felt like this for a very long time. As a flower, I was soulless. I lacked the power to love other people. However, with everyone's souls inside me... I not only have my own compassion back... But I can feel every other monster's as well. They all care about each other so much. And... they care about you too, Frisk. ... I wish I could tell you how everyone feels about you. Papyrus... Sans... Undyne... Alphys... ... Toriel. Monsters are weird. Even though they barely know you... It feels like they all really love you Haha. ... Frisk... I... I understand if you can't forgive me. I understand if you hate me. I acted so strange and horrible. I hurt you. I hurt so many people. Friends, family, bystanders... There's no excuse for what I've done."

- Asriel comes to terms with what he has done.

"... right. I understand. I just hope that... I can make up for it a little right now."

- Asriel if Frisk does not forgive him.

"Wh...what? ... Frisk, come on. You're... You're gonna make me cry again. ... besides, even if you do forgive me..."

- Asriel if Frisk forgives him.

"I can't keep these souls inside of me. The least I can do is return them. But first... There's something I have to do. Right now, I can feel everyone's hearts beating as one. They're all burning with the same desire. With everyone's power... With everyone's determination... It's time for monsters... To finally go free."

- Asriel before using the SOULs to destroy the barrier.

"Frisk... I have to go now. Without the power of everyone's souls... I can't keep maintaining this form. In a little while... I'll turn back into a flower. I'll stop being "myself." I'll stop being able to feel love again. So... Frisk. It's best if you just forget about me, OK? Just go be with the people who love you."

- Asriel reveals that he will turn back into Flowey without the SOULs.

"Ha... ha... I don't want to let go..."

- Asriel if Frisk comforts him.

"Frisk... You're... You're going to do a great job, OK? No matter what you do. Everyone will be there for you, okay? Well... My time is running out. Goodbye. By the way... Frisk. ... take care of Mom and Dad for me, OK?"

- Asriel's last words.

Trivia

 * Flowey acts as the true main antagonist at the end in place of the lead-up main antagonist, Asgore, due to the latter being revealed as a kind and sorrowful character.
 * If one backtracks a bit after certain points, they can catch a quick look at Flowey for a split second before he retreats underground, showing that he's been stalking the player, even up to the end of the game.
 * If the protagonist has killed Toriel at least once before, then reset or load the game and spare her, Flowey tells them not to get cocky and proceeds to taunt them by pointing out what they had done: "You murdered her. And then you went back, because you regretted it". He informs the protagonist he previously had the power to SAVE and reset, and that he played as the world's god before the protagonist's arrival superseded his. He tells the protagonist that he will be watching them.
 * Flowey's real name Asriel Dreemurr is an anagram for "serial murderer".
 * His name is also a reference to Azrael, The Angel Of Death from Judeo/Christian mythology. This is implied by his final form resembling the Delta Rune, which Gerson refers to as "an angel of death," and several other death related themes revolving around his character.
 * His name is also a portmanteau of his parents' names: As from Asgore, riel from Toriel.