King Slime is the first boss in Epic Battle Fantasy and the ruler of Slimes in said game. He appears as a giant slime with a brick tower on top of it where NoLegs sits with a mounted cannon, there are also two swords and a spear stuck in slime's back.
While this character only appears in Epic Battle Fantasy many foes in subsequent games are based upon his design: all variations of Kitten Forts, Giant Slimes, and Giant Bushes.
Defeating this boss will award the player with the King Slime Medal on Newgrounds.
- Easy Mode: 56,000 HP. Can hit both players for ±3000 Damage
- Normal Mode: 70,000 HP. Can hit both players for ±3750 Damage
- Hard Mode: 84,000 HP. Can hit both players for ±4500 Damage
- Epic Mode: 98,000 HP. Can hit both players for ±5250 Damage
- King Slime is the first boss of the Epic Battle Fantasy series
- It is actually unclear whether the title of "King Slime" belongs to NoLegs who rides on top of the Giant Slime or the slime itself
- The weapons on the back of the slime are a reference to some of the weapons used by Matt in the previous game - Brawl Royale
- As Furry Slimes that look like kittens are technically not cats, NoLegs seen in this fight is the only kitten in the game