Evil Mathew is a evil being who wants to destroy all of Deedle and take over the world.
He was originally the last of the Matthew race, besides Matthew himself, who was a bad guy and worked with Dabba to do evil things.He's also the evil nemesis of the incredible sulk and is hell bent on revenge because the incredible sulk once mistook him for a sqeezy toy and broke about every bone in his body. Evil Matthew, refusing to die, was turned into a cyborg by himself and Dabba.
Once Evil Matthew tried to destroy all of Deedle and take over the world, but Deedle eventually beat him after a long epic war, when Johnny Pickles ripped off Evil Matthew's legs. Then deedle banished him to the squiggle wiggle universe. While his real cyborg body is trapped in the squiggle wiggle universe, took possession of Matthew (a Deedle) and stayed in his body as a separate personality that was activated when Matthew wipes his face. Eventually Deedle killed the evil Matthew personality, and he is just in the squiggle wiggle verse.