Wyste

Wystes were vaguely worm-like aberrations from the Far Realm.

Description
Wystes were typically in diameter and  long. Their skin was translucent, showing the bizarre strands of organs inside of the creature. The "head" consisted of a sucker mouth ringed by claw-tipped tentacles.

Behavior
Wystes acted purely on instinct, attacking anything that came close.

Ecology
Wystes were native to the Far Realm, but could be found in underground pools of alien slime on the Material Plane thanks to gates to that maddening plane. They were preyed upon by dharculus. Wystes could be found dwelling in the settled lands of the Upperdark in Underdark.

Outside of the Prime, wystes inhabited the 222 level of the Abyss - Shedaklah.