The Amoebas

The Amoebas are microscopic guests who visit The Furchester Hotel in the episode "Toast with a Smile." Funella Furchester spends most of the day attempting to count them to make sure they're all present so she can check them in, which takes up her time and prevents her from serving Harvey P. so Elmo volunteers to fulfill it instead. She manages to count at most 99 Amoeba.