The Toxic Sludge is a monster in the slime family that spawns only in Hard Mode worlds, usually Underground in the rocky dirt layer. They will attack the player on sight.
- The Toxic Sludge, Hoppin' Jack, and Pet Baby Slime are the only Slimes to have visible facial features in the game.
- This is one of few Slimes that does not have the word "Slime" in it. The other ones are Pinky, Gastropod, and it's Spectral Variant.
- Toxic Sludge is one of the few enemies in Terraria to feature a smile. The others being Snowman Gangstas and Snow Ballas.
- Now drops a Toxic Sludge banner every 50th kill.
- Now has a chance to drop a Bezoar or Slime Staff.
- Added to the game.