Venom oozes were dangerous offshoots of ochre jellies. Their 12 ft (3.7 m) bodies were bright yellow and had large pseudopods that they used to move forward, dripping glistening slime as they did. These oozes smelled like bile. They were particularly good at both swimming and climbing, and were extraordinarily strong.
These bile-colored oozes constricted and grabbed their foes, as well as slammed them. Whilst their prey was grappled, they would release lethal poisons. They could also poison large quantities of water. Venom oozes could heal quickly, and were completely immune to acids, as well as cold and electrical attacks.
Like other oozes, slimes, and jellies, venom oozes moved through subterranean tunnels in search of prey. They preferred to constantly be on the move, instead of waiting on ceilings ready to drop on unsuspecting foes.
These deadly creatures were most likely to be found alone, but it was not unheard of for them them to serve more intelligent beings. Venom oozes could adapt to almost any type of environment, but they were naturally found near toxic vents, lakes of poison, or in moats and pits if kept by others.
Venom oozes originated from subjecting ochre jellies to different kinds of poisons, both magical and chemical, by members of House Freth. The house was later destroyed, but the venom oozes they had created lived on, and came to populate different parts of the Underdark.