Rhino Cat was a filthy human enemy of the Irken Empire who was dealt with in the most painful way by Almighty Tallest Red. The Rhino mutant was an obese, disgusting cave troll-like creature from planet Earth. He was once an ordinary obese human meat boy who supposedly mutated in a freak sewage pipe overflow accident by jamming the pipe when everyone on planet Earth for some reason flushed their toilet all at once.
Before he was mutated, he was a school bully who used to beat up kids younger than him. He later became an enemy of the Irken Empire on an Earth street when he belly flapped Tallest Red into a wall and made fun of the Tallest's red hair-which he was wearing as disguise when he was trying to assassinate Zim at the time. Rhino Cat Dave is actually believed to be the bully’s nickname, as no one would willingly call their child Rhino or David, for that matter. He also belly flapped DJ, an autistic human. Tallest Red became friends with him during his stay on Earth. Eventually, Tallest Red and DJ got payback on the bully by trapping him in an elevator with an angry dog and a lobster.