Sinister Slug is a recurring villain from Spongebob Squarepants. He is one of the many foes of Mermaid Man and Barnacle Boy. He is a terrorous slime creature that lives in the sewers.


In "The Bad Guy Club for Villains", Sinister Slug crawled out of the sewer and wormed up to a gathering of other villains. These were Man Ray, The Dirty Bubble, Atomic Flounder, and Jumbo Shrimp. They were banding together to make a team, known only as BGATFBC. Mermaid Man and Barnacle Boy watched them from an alley and suspected something was up so they tried to stop them.

The BGATFBC held their meeting at Hotel Evil, where Mermaid Man and Barnacle Boy showed up on the scene with a few other superheroes and fought with them. In battle, Sinister Slug slid up the wall and vomited a ball of slime at Mermaid Man. Mermaid Man jumped out of the way and the slimeball blasted Atomic Flounder instead. The slimeball was so sticky that it immobilized Atomic Flounder and stuck him to the ground.

Mermaid Man used The Bronze Hairnet's hairnet to capture all of the BGATFBC members and make them talk. They said that "BGATFBC" stood for "Bad Guys All Together For Book Club" and that they couldn't imprison them for reading. Mermaid Man said that this was right and let them continue their book club.

Powers & Abilities

  • Slimeballs - Sinister Slug can vomit slimeballs at people. When struck by the slimeballs, the target becomes immobilized and incapacitated, as the sticky slime leads to them becoming stuck to the floor.
  • Climbing - Sinister Slug is sticky enough to climb up the walls.




           SpongeBob Villains

Main Antagonists
Plankton | Karen Plankton | Mr. Krabs | Squidward Tentacles | Patrick Star | Mrs. Puff

Recurring Antagonists
Flying Dutchman | Man Ray | Dirty Bubble | Jumbo Shrimp | Atomic Flounder | Sinister Slug | The Moth | Bubble Bass | Plankton Family | DoodleBob | Squilliam Fancyson | King Neptune

Movie Antagonists
Dennis | Victor | Boat Jacker | The Thug Tug Gang | Cyclops | Burger-Beard

One-Time Antagonists
Every Villain Is Lemons | Kevin C. Cucumber | Abrasive SpongeBob | Alaskan Bull Worm | Puffy Fluffy | Sergeant Sam Roderick | Tattletale Strangler | Lord Poltergeist | Carl | Big One | BlackJack SquarePants | Evil Alien Jellion Overlord | The Moth | Hash-Slinging Slasher | Con Man | Master Udon | Evil Syndicate | King Gorge | The Mawgu | Don Grouper | Gordon | Coupe | Triton | The Fisherman | Madame Hagfish | Dead-Eye Plankton | Art Appraiser | Miss Gretel Puss | Planktonamor | Dreaded Patrick | Karen 2.0 | Captain Scarfish | Dragon Jellyfish | The Jellions | SpongeBot SteelPants | Robot Plankton | Globulous Maximus | Flats the Flounder | ToyBob | Gale Doppler | Mini Doodles | Plankrab | Doctor Negative | Jelliens | Seymour Scales | Cuddle E. Hugs | Animatronic Hieronymus Glove

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