From Introduction:
What you first mistook for a snake remarkably seems to be a pair of tentacles sprouting from a central stump of a head. Its clammy greenish skin glistens with moisture as it throws a tentacle towards you with surprising speed and agility.
These small but vicious predators lurk underground, grabbing whatever prey foolishly comes in reach. Its tentacles exude a rough, gritty substance that help it grip almost any surface. The creature weighs about 30 pounds. Screeching stranglers range in color from olive green to black, and often have a mottled, moist appearance. Sages believe that the screeching strangler was the prototype for whatever dread intellect created the choker. Rangers and druids maintain that the creature is instead related to the grick. Screeching stranglers rarely communicate. When they do, they speak Undercommon in a horrific, grating voice.