Nexus

Nexus is the final form of a biological entity.

Background
Nexus was formed from a mutation within a Vaporeon that occured suddenly at the peak of Acid Peak. Originally forming from the Sewers beneath the school due to a vile reaction with the ladder, Nexus in any of his forms began to wreak havoc on the world. Sporting abilities such as converting enemies into goo beings like himself, Nexus is quite the terrifying building. Nexus is responsible for the take-down of thousands of ISIS soldiers, and the destruction of the Military Tunnel and base.

Trivia
I don't even know what's going on in that picture.