Brother Blood is a major recurring antagonist from Teen Titans Go!. He was a malevolent and spiteful old man, who servered as the headmaster of H.I.V.E. Academy as well as the archenemy of Cyborg. He is most important for being the inventor of Pain Bot, his former sidekick and the current little buddy of Cyborg. He dies in Season 5 and serves as a posthumous antagonist for the rest of the series.
Brother Blood made his first appearance in "Waffles", where he kidnapped Cyborg and Beast Boy, (who at the time, were saying nothing but "Waffles") and plotted to torture them with the help of his trusty torture device, a newly invented robot named Pain Bot. Robin, Raven, and Starfire tried to stop him, but Brother Blood trapped them too and forced them to watch as Cyborg and Beast Boy were mercilessly ripped apart, electrocuted, burned alive, and blown apart by Pain Bot. All the while, they kept saying nothing but "Waffles". Robin, Raven, and Starfire took it upon themselves to torture Brother Blood by doing nothing but saying and signing "Waffles", which drove him to madness. Brother Blood ran out of his evil lair, flailing and screaming, setting the Teen Titans free.
In "Little Buddies", Brother Blood fought with the Teen Titans on the dark streets of Jump City at night. All of Brother Blood's attacks were to no avail as the Titans were too powerful for him. Just as Robin told him to give it up, Brother Blood unleashed his secret weapon. It was Pain Bot and he was back for revenge. Pain Bot tortured and maimed all of the Titans as Brother Blood watched and laughed in satisfaction. Starfire used her eye beams to black Pain Bot's arms off, setting the Titans free, so Brother Blood sent out another set of arms. While he did this, Beast Boy distracted Pain Bot by using himself as bait, while Robin took on Brother Blood by throwing a Birdarang at him and blowing him out of his boots.
After the destruction of Brother Blood, Cyborg started to like Pain Bot and he stole him and kept him for himself. Cyborg was able to train Pain Bot to act like less of a torture device and more of a little buddy. Since then, Pain Bot has remained a loyal and heroic friend to Cyborg, putting a new hero into the world and leaving Brother Blood without an ally.
In "Baby Hands", Brother Blood was wreaking havoc in Jump City with a giant laser cannon that was also a giant memory-erasing doomsday device. He tried to blast the Teen Titans with it so they would forget who they truly are. Recently, Robin had been unappreciated by the other Titans, so he thought that if they lost their memory, this could be his chance to mold them into better people. Robin tricked the other Titans into getting blasted by the memory eraser and Robin beat up and stopped Brother Blood before he could erase his memory.
Brother Blood later started stealing a bunch of weapons and the Teen Titans had to stop him. Robin had lied to the other Titans, claiming to have all the powers that they had, so they all expected him to bite off more than he could chew. Robin eventually had to come clean and tell the other Titans the truth so that they could handle Brother Blood, while Robin did nothing but sit around, choreographing them with his baby hands.
In "Accept the Next Proposition You Hear", Brother Blood was having stomach problems during a fight with the Teen Titans. He begged the Titans to make their fight quick because of his cramps. The Titans actually felt sympathy for him and made sure to make their battle quick and to the point. Brother Blood invented a series of mind control devices, which he attempted to use on the Teen Titans, but all of them were destroyed before he could use them. Robin had destroyed his last mind control device and was about ready to take him down when suddenly, Brother Blood voided his bowels and the stench made Robin pass out. Brother Blood said that he was having stomach problems. With Robin incapacitated, Brother Blood used his last mind control device on the other Titans to make them obey his orders. Before he could give them a single order, he got a huge stomach cramp and realized he needed to make a BM. So, he rushed to the bathroom and pooped. While he was in there, Robin awoke and snapped the Titans out of their hypnotic trance and they all escaped. After they left, Brother Blood came out of the bathroom, finally ready to fight, only to be disappointed with the fact that they left.
The Titans started reading fortune cookies and taking their advice from them. Eventually, the fortune cookies started giving them oddly specific orders, such as "Build a Metal Cage", "Punch Robin in the Face", "Lock Robin in the Cage", etc. Robin was quick to figure out that these cookies were made by Brother Blood. Brother Blood showed up there and told him his whole plan. He also said that he wasn't going to have stomach cramps because he's started eating healthier now. Robin got revenge on Brother Blood by doing bogus fortune-telling things on the other Titans. He read Cyborg's palms, told Beast Boy that Mercury was in retrograde, and showed Raven and Starfire a Magic 8-Ball. All of these things told the Titans to "Punch Brother Blood in the Face". That is exactly what they did and they eventually punched Brother Blood into the cage.
Brother Blood is an elderly, but strong and limber old man. He has pointed white hair that he has slicked up into devil horns. He has thick black eyebrows and dark black bags under his eyes. His face is very sculpted with chiseled features and pronounced cheekbones. He wears a black suit with a big red collar, red gloves, red boots, and a yellow belt. His red collar is lined with a yellow trim and a yellow picture of a skull.
Brother Blood is a maniacal and sinister old man, who is quite prolific and active for someone of his age. He is the wielder of a vast amount of political power and is recognized as a very well-respected man in the villainous community. He is also a genius inventor and he's built a number of doomsday devices such as mind control helmets, memory-erasing lasers, a giant butt, and most notably, Pain Bot. He is very easily annoyed as he was driven to madness in "Waffles", by listening to the Titans sing a song about Waffles a bunch of times.