He looks like pretty much any sludgepuppy. He has purple colored goo-skin. He walks, and has bulkier than usual arms and legs. His head is messy, and sounds like how an Earth would be like.
He has green eyes.
Willie was a kindhearted and considerate person who thought about the needs of others as well as his own. He was initially a very compliant person who could not even think about breaking the rules. This aspect changed later on after witnessing and experiencing his adventures with Fred on the G.P. Brisk II.
Powers and Abilities
He can stretch and use their stretching to shapeshift body parts. If he stretches too far, it might result in the part falling off. He can detach his body parts, and stick them back on, reattaching them.
He can shapeshift his body parts, and sometimes himself into other objects. Using his sludge, he can look like another shape made of purple sludge.
He is capable of regeneration.
His sludge is sticky, which gives him abilities like wall climbing.
He can fire his sludge as an attack.
He can be harmed by water, fire, or by scattering enough of his body matter to the point where he cannot reconstitute.
He appears in every episode of Season 2, excluding "Thrill of the Hunt".