The Leviathan is a secret Legendary pet in Bubble Gum Simulator. It was obtained by opening a Frost Egg. The chance of hatching it was 1 in 8 million (0.0000125%), or 1 in 4 million (0.000025%) with the Lucky Chances gamepass.
- This pet was hinted at in one of Isaac's tweets.
- This was the first secret pet hidden in an event egg.
- This was the second secret pet to be added to the game.
- This pet has 5 reskins, which are Sylently's Pet, Gryphon, Rainbow Gryphon, King Leviathan, and Peppermint Leviathan.
- The Leviathan is featured in Tophat (F) and Trophy.
- In Update 44, this pet's size was increased due to previously being a lot smaller than other secret pets that came in the later updates.