Black pudding

"This creature resembles nothing so much as a roundish blob of inky black goo."

- Skip Williams, Monster Manual 3.5

A black pudding was an ooze resembling a bubbling, heaping pile of thick black goo.

Description
The average black pudding measured 15 ft (4.6 m) across and 2 ft (0.6 m) thick and they weighed around 18,000 lb (8.2 mt). While most of these monsters were an inky black, some could be brown, grey, and even white. In underground locations, these creatures appeared as dark blobs.

Behavior
These creatures were mindless underground-dwelling scavengers that wandered and absorbed whatever they found. A black pudding would position itself in a dungeon hallway like a shadow and wait for unsuspecting prey.

Combat
Black pudding attacked by grabbing, grappling and constricting prey directly into their liquid-esque mass. Like other oozes, they also secreted a deadly acidic substance which strongly and quickly dissolved weapons, clothing, and organic tissue alike. When slashed at or pierced, the black pudding split into two smaller puddings, both of which would do the same; this continued until they were too small and weak to do so further. A black pudding would eat bone, metal, and wood leaving only stone behind.

Ecology
Like other oozes, black pudding desire warmth and sense their prey through movement. While the creatures seek living and breathing targets, they will feast on animal guts, slime, and mushrooms.