The Slinker is a Gem Monster that first appeared in "Reformed", serving as the episode's antagonist, and later in "Unboxing", serving as a minor antagonist.
She resembles a dark, flowering plant. The monster consists of four dark-blue petals, which acts as her mouth, and are light-blue on the inside. Each petal also has five thorn-like projections nearing the tip. The petals are connected together by a darker-blue bulb that tapers to a point. The bulb is connected to multiple vines used as appendages, with two vines having a leaf-like structure at the end.
At some point in time the Slinker enters the Crystal Temple. She is first spotted by Pearl, who later informs the other Crystal Gems of the Gem Monster's presence. After discovering the tunnels the Slinker had dug within the Temple, Garnet begins to pursue the creature inside Amethyst's Room. Amethyst and Steven later join Garnet in her search. Despite their combined effort, the three Crystal Gems struggle to capture the Slinker. The Corrupted Gem is able to poof Amethyst four times, stalling her pursuers in each instance and using the opportunity to escape. After Amethyst poofs for the fourth time, the Crystal Gems defer their search to regroup at the Beach House.
Physical Vigor: The Slinker is a very fast, limber, sturdy creature, able to withstand multiple hits from Amethyst and Garnet. She also has great physical strength, able to force Amethyst to retreat to her gem with a single bite from her "jaws" or a squeeze from her tentacles.
Stealth: As her name implies, the Slinker is proficient at moving quietly and hiding. She often employs this ability to evade and ambush her foes.
Burrowing: She is able to move through the ground with ease, forming circular tunnels that lead into different parts of Amethyst's Room.
Prehensile Appendages: Her vines are very prehensile, able to entangle enemies with a tight grip to the point of constriction.
Projectile Goop: She can secrete a dark, ink-like substance that she seems to be able to shoot across long distances.