Puyoyon

Amoeba is a blob-like robot in Mega Man 4. It is native to Toad Man's stage, and mainly is in the first part of the sewers after passing the rainstorm. It can stick to the ceiling as well as move on the floor.

Trivia
"Puyo" is Japanese for "blob".

Similar enemies
Enemies similar to Amoebas.
 * Thunder Slimer
 * Rimblemenji