She appears as a gigantic brittle star, with a massive disk and short arms. The upper portion of her disk appears as a giant mound of turquoise colored crystals with multiple geometric facets. The lower-half of the disk is colored dark turquoise. The arms are joined near the middle of the disk and taper to a point outwards, they are of a darker shade of turquoise. The ventral side of the disk contains a drill-like apparatus that can unfurl to reveal five turquoise colored arms, and appears to have fingers, that surround a mouth. The dorsal side of the disk houses multiple Drill Parasites that furl themselves to form spike-like protuberance that the Gem Cave Creature can launch.
The Crystal Gems were attacked by her, in which Garnet successfully managed to defeat her, and proceeded to bubble her gemstone.
Burrowing: The Gem Cave Creature has the ability to burrow underground by using the drill underneath her disk.
Body Manipulation: She can unfurl her drill to produce five more arms to enhance her fighting capabilities. Her arms also have the ability to stretch to great lengths, as seen when she was battling Garnet.
Enhanced Durability: Her body is presumably durable enough from attacks, as Garnet had to get close to her and hit her weakest point, which was her mouth.
Creature Creation: She can also launch multiple spikes from her disk, which can unfurl and become Drill Parasites that can aid her in battle.
Gem Cave Creature resembles Brittle Stars more than a Starfish.
Brittle Stars (Ophiuroids) resemble true Starfishes/Sea Stars (Asteroids), but the main difference is that brittle stars have a distinct central disc and five radiating slender, highly flexible arms. The arms are solid and not hollow like the sea stars, whose central disk and arms are inconspicuously parted.
She is featured as an enemy that Steven must avoid in Gem Bound, as well as a second yellow variety.