Fillerbunny is a pink bunny. It appeared for first time in the Johnny the Homicidal Maniac and later had it's own spin-off: Fillerbunny (comic).
There was a lot of fan speculation once Fillerbunny received its own comic, as it was once drawn as, quite literally, a filler for the comic. When it was drawn much better in the comic, some fans cheered, while many were against this comic. He has a cameo appearance in the Invader Zim episode Dark Harvest where he's shown in a jar filled with purple liquid in the opening shot.
