The Jellyfish is a members only underwater pet. It was released in April 2012, and is sold from the "Choose a Pet" menu.
- Clicked: Stretches out legs and strums them like a guitar.
- Pose: Puts left tentacle on "hips," and holds up right tentacle in the air as if modeling.
- Dance: Sways from right to left.
- Dive: Dives up and down headfirst.
- Swirl: Swims in a circle.
- Play: Glows brightly and dives upward.
- Viking Helmet: This is supposed to put a horned helmet (like the Viking Hat) on the pet, but it changes the pet's head into a pie instead.
- Pie Head: This is supposed to just change the pet's head into a pie, but it also adds the Viking Helmet accessory.
- UFO Head: This changes the pet's head into a UFO with an alien inside.
- Cupcake Head: This changes the pet's head into a frosted cupcake.
- Chef's Hat: The pet wears a large, white chef's hat on its head.
- Asian Conical Hat: The pet wears an Asian Conical Hat on its head.
- Sunflower: The pet wears a sunflower on the side of its head.
- Cactus: The pet's regular head is replaced with a similarly-shaped cactus.
- Jetpack: The pet wears a jetpack on its back.
- Pinwheel: The pet holds a pinwheel that sticks out behind it.
- Dual Samurai Swords: The pet carries a dual-set of black samurai swords.
- Lollipop: The pet carries a large lollipop that sticks out behind it.
- Snorkel: The pet wears a large snorkel that consists of a wide pair of goggles and a long mouthpiece.
- Moustache: The pet wears a thin, curly mustache that curls at the ends.
- Fancy Eyes: The pet gains a pair of shiny, blue eyes with long eyelashes.
- Glasses: The pet wears a pair of large, blue-framed eyeglasses.
- Similar to Deer and the Gecko pet, there was a puzzle the Jammer had to solve to foreshadow their release.
- They were released alongside the Octopus.
- When clicked, Jellyfish plays music with their arms like a guitar.
- They are the only pet that can be set with no eyes.
- There is a glitch with the rare pie accessory that causes it to also include the viking helmet accessory.
- There is a glitch with the viking helmet accessory that causes it to appear like the pie accessory.