The Slime Mutant was the disguise of Prof. Emmanuel Raffalo.
The Slime Mutant was a humanoid skeleton covered in a green slime.
Powers and abilities
The Slime Mutant could shoot large amounts of a liquid which can cocoon people. The liquid was revealed to be Fruitmeir's dessert.
Scooby-Doo! Mystery Incorporated
The Slime Mutant lurked below Crystal Cove and attacked people underground. After a confrontation with it underground, Mystery Incorporated eventually caught it, taking off its mask to reveal Prof. Emmanuel Raffalo underneath. Their teacher was using passageways from Fruitmeir's to the sewer system to steal from the Crystal Cove Bank. (Beware The Beast From Below)
When the Evil Entity's power source, the crystal sarcophagus, was destroyed, a black hole was created, sucking it in. This caused a chain reaction, altering reality for all of Crystal Cove, leaving the town unnaffected by its negative influence, and therefore Raffalo didn't try to scam the town as the Slime Mutant.
- Scooby-Doo! Mystery Incorporated
- In the online game Scooby-Doo! Mystery Incorporated Crystal Cove Online, the Slime Mutant costume is put on display at the Spook Museum.