Mud Alien (Samurai Jack)

These sludge-like entities appeared in Samurai Jack, episode "XCII".

Overview
They were allowed to depart from their world to Earth by the demon Aku during reign of tyranny. They appeared to be made entirely of mud and possess yellowish eyes. Without Aku's tyranny, this race may never had transferred to Earth.

History
A numerous group of this species is shown briefly in the episode, where they made a totem in Aku's likeness out of sludge as tribute before telling them to leave.