Toxic Sludge

The Toxic Sludge is a Hardmode slime enemy that appears in the Underground layer in place of normal slime enemies. They deal a vastly increased damage from normal slimes, and they also have a 50% chance on hit to afflict the player with Poison. They drop gel like the other slimes.

Trivia

 * The appearance of the Toxic Sludge appears to be a homage to similar enemies from the SNES game Yoshi's Island.
 * They look a bit like "Hairy Beast" (resembling the two teeth)
 * It is one of 3 slimes to not have "Slime" in its name
 * This may be a reference to the sludge Pokemon, "Muk"