Professor Venomous is a major antagonist. He is voiced by Steven Ogg.He is a bioengineer in Antagonistan, as well as lord Boxman's husband. He can often be seen next to Obake, since they both work in the same laboratory.
characteristics: tall, slender, purple skin, black hair, black eyes, sharp teeth, handsome, evil, sadistic, usually calm, diplomatic, comedic, patient, indifferent, cruel, intelligent, power-hungry
real age: 3 real years
species: mutated human
subrace: negative character
comes from: OK K.O.! Let's be heroes
family: lord Boxman (husband)
nicknames: Boxman calls him "P.V.".
- Fink: As his minion, Fink can often be seen alongside him. The two share a father-daughter-like relationship, even though they do not see it as such, with Venomous referring to her simply as his minion, and with Fink seemingly having a crush on him. However, they deeply care about each other.
- lord Boxman: Their relationship does not play a big role, but from what it is shown, they are pretty happy together, despite being villains.
- Obake: Obake is among the scientists, whom professor Venomous has the most interactions with (with the other ones being Boxman and Varian). They get along pretty well, despite working in different departments (Venomous is a bioengineer and Obake is a technology expert).
- Varian: Professor Venomous, along with Obake, acts as a mentor-like figure towards Varian. He treats the alchemist with a lot of support and patience, and can be seen sometimes offering him advice. However, Venomous was among the toons, who showed doubt in Varian's idea about giving Snake a chance.
- Roy Mustang: Roy is among the animated humans who were kidnapped and turned into mutants by professor Venomous. As a result, Roy has a passionate hatred towards the professor, to the point that he did not hesitate to punch him in the face after returning to his true form.
- Diane Amara: As revealed in the episode The human thief, they do not get along, despite being colleagues. In the episode, Diane accused him of stealing her mutation formula, to which he completely denies. Their rivalry was a very minor plot point and it only served as a comedic effect.
- Toffee: Venomous and Obake have a mutual respect for their majordomo. The three characters can often be seen together. He respects and trusts both of them. Some antagonists say that Venomous is Toffee's favorite bioengineer (similarly to how Varian is thought to be his favorite alchemist).