Gwoemul

Gwoemul (also known as The Monster) is a fish-like mutant and the main antagonist of the 2006 South Korean monster film, The Host.

Despite being mute, its vocal sounds are provided by Oh Dal-su.

Personality and Traits
Gwoemul is an extremely carnivorous, bloodthirsty, aggressive, man-eating, ravenous, hungry, violent, and dangerous creature that would often hunt humans near the river, bringing them back to its lair in the sewers alive or not to feast on their flesh. It seemed to have cruel and cunning side, as it pretends to sleep so it can kill any captured prey that turned out still alive when brought to its lair.

Gwoemul also has a bizarre habit. Whenever it senses liquid splashing around it in the form of rain (whether or not the liquid actually IS water), it will tilt its head back and catch the liquid in its mouth, gulping it down single-mindedly. In one instance the liquid was gasoline, but it continued to perform this strange ritual. Why it had such an odd ritual may relate to the dumped formaldehyde that responsible for its mutation: Though not confirmed, it is possible that when it was either a fish or tadpole, it drank the dumped chemical and upon realizing its effect, it became addicted with the said liquid and lose its focus on another. This strange habit proved to be its downfall, as the gasoline it consume eventually set it on fire by protagonists before being impaled to put out its misery.

Physical Appearance and Biology
Gwoemul has a tadpole-like design with a massive mouth that can open in flaps surrounded in teeth, gills, two eyes, a long whip-like tongue that it tucks inside the opening of its mouth, two rows of fins on its tail, and arms with two small feet located directly behind the arms. It can use its tail not only for support while swimming, but also for support while climbing and grabbing prey. It also has a few fish stuck on its back to show its mutational side. During the climax, the fish fall out of the creature as it stands up from the Agent Yellow chemical and are shown flopping on land, meaning they were still alive while they were connected to the beast.

Similar to an amphibian, Gwoemul can both breathe air through its lungs and gills. It traps humans in its mouth and regurgitates their bodies out into a moist encloser to consume them later or just trap them and leave them to die. It also licks its tongue on the spat out bodies to make sure they are either still conscious or dead. After its prey is fully consumed, it vomits out their bones as it is unable to decompose the skeleton.

History
Gwoemul's origins are brief, yet understandable. In late 2000, an American military pathologist and his Korean assistant dump 200 bottles of formaldehyde down a drain leading to the Han River near Seoul. Over the years, there are sightings of an amphibious creature in the water, fish in the river begin dying off, and a suicidal man spots something moving in the water before jumping from a bridge.

One day, as Park Gang-do, a man who runs a snack shop in a park near the Han River along with his father Hee-bong, delivers food to customers, he and several others spot a dark figure in the water of the river. The people begin throwing cans into the river to scare it off, but are attacked by a treacherous creature that emerges from the river and runs loose throughout the city, eating several people whole and injuring many others. Gang-do spots his daughter, Hyun-seo, in the crowd and grabs her, but only after tripping he realizes he grabbed a different girl, before witnessing the monster grab Hyun-seo with its tail and diving back into the river. Gang-do and his family are taken to a hospital by American military officers, as Gwoemul is believed to be a host to a deadly virus.

Meanwhile in a small section of the sewer, after killing two chemical scientists, Gwoemul regurgitates several of its victims in a hole to consume them later, including Hyun-seo, who hides from Gwoemul's sight in a small pipe opening. Gang-do (learning that his daughter is still alive via phone call) escapes from the hospital with his father and siblings, Nam-il and Nam-joo, to track the monster's location. Two homeless boys are swallowed by Gwoemul that night and Hyun-seo helps the only regurged survivor, Se-joo, into the pipe with her.

The family discovers Gwoemul wandering about next morning from within their snack shop and shoot at it, only aggravating it enough to tip the entire shack on its side. Hee-bong allows himself to be killed by Gwoemul to let his kids escape from the beast. The siblings are then taken back to the hospital, where they eavesdrop on scientists discussing that there was no virus, only a myth made up to hide the creature's origins. With the help of a homeless man who is also in the hospital, the three are able to escape.

Back in the sewers, as Gwoemul vomits out the skeletal remains of its prey, it attacks Hyun-seo and Se-joo when the latter starts to cry, but is unable to reach them through the pipe. As it rests, the two kids make a rope out of the victims' clothing to escape from the hole, but realized it was too late that Gwoemul only pretended to sleep to lure them out of their hiding spot, and are swallowed up by Gwoemul before they are able to return to said hiding spot.

Gang-do finds Gwoemul's hiding spot only to find it empty. While investigating, he spots the monster passing above him with Hyun-seo's arm hanging outside its mouth and gives chase, stopping Nam-joo from firing an arrow at it when it passes her, fearing she may injure Hyun-seo. The two then chase Gwoemul to the other side of the river, where a protest is occurring from the army preparing to dump a toxic chemical known as Agent Yellow to kill the creature.

When Gwoemul makes it to the shore and begins attacking the crowd, the army open up the container with Agent Yellow inside, covering Gwoemul and the crowd. As Gwoemul falls unconscious and the crowd flees, Gang-do pulls out Hyun-seo and Se-joo from Gwoemul's mouth, only to be horrified to discover that Hyun-seo has been killed by the beast. Enraged, Gang-do attacks the creature when it awakens and manages to hit it with a metal pole, but is quickly overpowered. Nam-il comes to his brother's aid by throwing Molotov cocktails at it while the homeless man pours gasoline on it, which Gwoemul foolishly drinks. Nam-joo sticks a flaming piece of cloth from one of the bottles on an arrow and fires it straight into Gwoemul's eye, setting it ablaze. Before it is able to escape into the water, Gang-do impales it through the mouth with the pole, finally killing the monstrous mutant.

Trivia

 * According to the director, Bong Joon-ho, Gwoemul's inspiration came from an article based on a deformed fish with an S-shaped spinal cord being caught in the Han River.
 * The original title of the film is Gwoemul, which is Korean for "Monster". It is unknown if its name is mentioned in the film.
 * The monster, under the name Tadpole Thing, was ranked #10 on Cinemassacre's "Top 10 Giant Movie Monsters" list.
 * The monster was ranked #6 on Watchmojo's "Top 10 Lesser-Known Movie Monsters" list under the name Mutated Fish Creature.