Orange Spodumene

The "Worm Monster" is a corrupted Gem that first appeared in "Bubble Buddies".

Appearance
As its name suggests, the corrupted Gem takes on the form of a giant worm like monster. It is relatively long and the width of its body is nearly equal throughout its entire length with one end enlarged into a sphere, the head, where the mouth is located at the end. The body is colored brown with blue and purple spots scattered across it. Its entire body and head is covered in a thick shiny translucent light blue coating that produces five tentacles near the mouth. The mouth is circular with multiple rows of white teeth present with each individual teeth in a circular arrangement in each row. It has a red gem and is located inside of its mouth and gives off a red glow that passes through the skin and coating giving the illusion of eyes on the head.

Abilities
Due to living in the water, the Worm Monster is a great swimmer. It has roars so loud that it can cause disturbance on land ranging from mild tremors to being able to break off parts of structures. Its ability to swim is not limited in a watery medium, it also has the ability to burrow underground and can move in high speeds underneath the earth. The Worm Monster's body also has great tensile strength as it was stretched around multiple times on the pillars of a pier before reaching its limit. Although the monster has no eyes, its ability to sense objects and organisms around it is surprisingly well enough that it was able to sense its favored food, Connie's bracelet, and not bumping into anything while on land.

"Bubble Buddies"
In "Bubble Buddies", the Worm Monster was first seen at the bottom of the ocean, eating glowing seaweed. It possessed a habit of burrowing into the ocean floor, resulting in frequent tremors and loud screeching to erupt throughout Beach City.

After falling to the bottom of the ocean, Steven and Connie see the Worm Monster for the first time. The creature then dives into the ocean floor, causing the ground to shake and crack open, making Steven and Connie fall into a pit. The monster reappears after Connie and Steven reach the surface of the ocean and chases them to shore. Steven notices the creature is attracted to Connie's bracelet because it glows. Grabbing it, he leads the monster around the pier supports, causing them to break and crush the Worm Monster beneath the pier, the Worm Monster then explodes and Garnet bubbles its gemstone.

Trivia

 * It was revealed in the episode, "Ocean Gem" that the Worm Monster, along with other monsters were just corrupted gems.
 * Though named Worm Monster, it resembles much more to a sea cucumber of the family Synaptidae.
 * The worm monster's gem reappears in the online game, Heap of Trouble.