In the Ultimate Marvel series, Sergei Kravinoff is a Russian-Australian and the host of his own TV reality show. In the TV show, he hunts down dangerous animals and intends to hunt and kill Spider-Man on live television in order to boost his ratings (after his first fight with Doctor Octopus attacking Justin Hammer's NY facility). He is arrested after being knocked out with a single punch by the superhero (who was trying to help two people out of an overturned car) and his show is cancelled.
In the Ultimate Six story arc, Kraven genetically tampers with his DNA, allowing him to become a gruesome creature with large hands and feet, claw-like fingers, enlarged red veins, darker skin, fang-like teeth from a near lion-like snout, cat-like eyes, and berserk-like feral behaviour. After being interviewed on a talk show where its host questioned him about the "enhancements" he took, Kraven is confronted by the Ultimates for tampering with his DNA despite his lawyer's attempt to defuse the situation as Wasp disables the camera that was filming them. He flees before being taken down by Hawkeye. When being taken to his cell by Sharon Carter, Kraven assumed his second form before being shocked by the inhibitor collar on him. Kraven eventually escapes from the Triskelion with other Spider-Man villains Green Goblin, Doctor Octopus, Electro, and the Sandman. They capture Spider-Man, tie him up, unmask him, humiliate him, and blackmail him into joining their group as its sixth member. On Kraven's part, he blamed Spider-Man for the cancellation of his show, his arrest, his deportation, and his wife leaving him as Norman Osborn keeps Kraven from killing Spider-Man as they need him alive. Kraven helps with the attack on the White House, though he is electrocuted by a lightning bolt from Thor when he tries to attack Peter. He is last seen in another S.H.I.E.L.D. containment facility strapped to a bed and surrounded by armed soldiers. Kraven claimed to them that he was under mind control and that he wasn't sure if Green Goblin or Doctor Octopus was responsible.
Alongside the rest of the Ultimate Six, Kraven (who no longer sports his animalistic enhancements) plays a role in "The Death of Spider-Man" storyline. Norman Osborn breaks him and the rest of the Ultimate Six out of the Triskelion and, after their escape, Osborn informs them that God wishes for them to kill Peter Parker as they reform the group, with the Vulture as a replacement for Spider-Man. When the Ultimate Six went to Tinkerer for some weapons, Kraven claims a set of blasters and knives while stating that he is starting a tab. When Electro is shot by Aunt May, an electric surge knocks out Kraven, the Sandman, and the Vulture.
