What Happened To Every Version Of The Hulk?

One of the more transparently evil Hulk forms, the Devil Hulk exists as a manifestation of both Banner's dark side, and his concerns around the Hulk being an evil entity. In Immortal Hulk #15, it's suggested that this form also exists as a sort of father figure to Banner - only, since his dad was abusive, this Hulk form is a complete monster as well.

As such, the creature resides deep within Banner's mind, only appearing to him in The Incredible Hulk (Vol. 2) #19 after the scientist is experimented on in a manner that shows him all of his potential alter egos.

The Devil Hulk escapes into reality several times, the most disturbing of which takes place in The Incredible Hulk #27, and sees the monster trap Banner in an imaginary dream world, while he mercilessly kills and maims out in the real world. The Devil Hulk hasn't appeared in any major storylines for some time, but it's only a matter of time until he appears once more to make the Hulk into something even more terrifying.