Years ago, the Hippo was just that – a regular hippo living in the zoo until the High Evolutionary came along and changed his life forever. In the name of science, the hippo was transformed into the Hippo – a semi-human creature belonging to neither race. Hippo tried to make a go of it in the real world, but when things weren't going his way, he started robbing banks. Managing to stay under the radar for quite some time, Hippo's luck ran out when the sinister Spider-Man took notice of his evil ways and bit his legs off.
Hippo eventually found himself in the care of the Redeemer, or rather his alter-ego, Dr. Shep Gunderson, and was drafted into Gunderson's therapy group. Surrounded by others who have shared a similar fate, the Hippo was eager to dish out some revenge to the man who maimed him. Replacing his missing limbs with metal appendages, the Hippo was ready to go. Unfortunately, he was believed murdered, along with his teammate, Eleven, and the two were reportedly eaten by the very creature they sought to save.
* Note: The details of Hippo's death may have been grossly exaggerated as two members of the Avengers, the real Spider-Man and Ronin, were seen battling the creature just before Luke Cage dropped on his head, rendering him unconscious.