Sludge

"Everyone can take its powers but they not sure they want to touch it." Sludges are Titans that are as the name implies, made out of toxic sludge and are more poisonous and revolting than Stenches.

The Sludge was created by Dr. Neo Cortex but was used by Nina Cortex in Crash of the Titans. It is a mutated toxic sludge that specializes its slime for attacks; it can extend or expand its arms to attack its foe. Its slimy body also gives it the ability to shapeshift; it can sink into the ground and form a slug-like form to block and then come up from behind and punch the enemy with an uppercut. It also vomits a highly venomous acid that poisons Crash and other foes; when a Titan gets poisoned by Sludge's toxic venom, the Titan will be engulfed by a toxic green gas signifying it was poisoned. When Crash attacks the poisoned Titan, the Titan will be instantly stunned. In Mind Over Mutant there are some NV-free Sludges living in the Junkyard.

Biology
Sludges were bipedal, chameleon-like titan that are made from toxic waste. Sludge's body is simply shaped toxic waste, with two or three toe-like structures on the feet, and gooey hands with three fingers and a thumb on arms which could extend to reach its victim more easily. The Sludge's head is round and forms a face with a Pinocchio-like nose. It could form itself into a mobile slug-like posture to block attacks and attack surprisingly with an uppercut (in both games). It also vomits venomous toxins which hurts victims every seconds. Sludges have a translucent body, being made of toxic waste. They resemble a chameleon/frog hybrid in Crash of the Titans, but in Mind Over Mutant, he resembles a warthog as opposed to looking reptilian.

Trivia

 * It is not yet sure how exact it was mutated though obviously it was mutated from a Pig and radioactive sludge.
 * When jacking Sludge, Crash doesn't ride on its back. Instead, Crash will sink inside the Sludge's belly.
 * It is the only titan that can stay in toxic substances without dying.
 * Sludge in Mind Over Mutant is different from the Sludge in Titans, possibly because they're mutated from different area, One is on Junkyard, the other one is from N. Sanity Island.
 * The Sludge is similar to the Pokemon Grimer and its evolved form Muk, because they're all made of sludge.
 * The Sludge is the only Titan that is able to move around freely while blocking in COTT, and the only one in COTT that can attack while blocking.
 * The Sludge's block movement is necessary to access certain locations in MOM, as it can go through gaps that are not tall enough for Crash to enter.