Source: Bestiary 4, pg(s). 103
A grothlut's body is a white, formless, legless, hairless, slug-like mass. In the fleshwarping process, arms become rubbery and lack strength; facial features smooth out—the nose sinks in, the cheeks widen and flatten, and the eyes become pale and seem to meld in with the surrounding skin..
Grothluts lose most of their intellect and can feel nothing but the pain of their transformation. When other creatures approach, they cry for release before lumbering forward to attack and feed.
Grothluts often patrol the periphery of drow settlements. When enemies come, they are the first to be thrown into battle for the purpose of softening and nauseating the enemy before elite warriors follow and cut them down.