Carnage has been revealed as DLC for Marvel Ultimate Alliance 2 on PS3 and Xbox 360.
The official website for the game has lead animator Adam Olshan chatting a bit about the differences between the character versus Spider-Man, and Venom, citing his viciousness.
"We used the word "vicious" a lot when talking about how he should look. "Crazy" too, because of the background of who he is and what he is. I worked mostly on his basic melee combat," said Olshan. "That's when we really pay attention to how we can differentiate that character. Spider-Man needs to be agile & springy. Venom was more of a bruiser, like a huge jungle cat who attacks with lethal clawed swipes.
"For Carnage, we wanted him to feel as quick as Spider-Man, but as dangerous as Venom (or worse). We ended up with a very "slashy" character. Carnage is like a lunatic knife fighter: cutting people up quickly and messily, without much concern for how he looks doing it."
No word on when this bit of DLC will hit the game, but to tide you over, Kotaku has some screens and video posted of Carnage for your consideration.