Amoebas are microscopic one-celled organisms that first appear in the episode "Patty Hype."
Role in series
They also appear when SpongeBob turns Plankton into a baby in the episode "Goo Goo Gas." He is shrunken down after being hit by the baby gas to microscopic smallness. The Amoebas are shown to say that Plankton's baby size is microscopic. He appears a third time in "Bottle Burglars."
Plankton also gets a pet amoeba in "Plankton's Pet" and names him Spot. Spot looks much different than the amoebas in "Goo Goo Gas." Spot makes another appearance in "Spot Returns" and has several children who are amoebas.
Amoebas are also featured in the mini-games of SpongeBob's Atlantis SquarePantis.