Mud Aliens

The Mud Aliens are a race of sludge-like entities who were allowed by Aku to live on Earth.

Background
They are seen in Episode XCIII, where they are seen paying tribute to Aku with a sludge totem in his likeness, much to his chagrin. Aku quickly remarks that they are making a mess, and tells them to leave. It is unknown how the past Aku's existence affected their existence.