Mr. Invisible
Mr. Invisible (also known as 隐形先生) is the entity that manifests itself when no other cat is occupying the feeder. Not much is known about him. There is a small fanbase surrounding him.
Behavior
Mr. Invisible doesn't seem to eat any kibble nor snacks. Mr. Invisible has never gotten into a conflict with another cat.
Appearance
Mr. Invisible is a normal cat, except he is invisible. His breed is unknown.
Sightings
He appears regularly, right after another cat exits the feeder. He's a very common sight.