Mini/Warriors

A mini-monster is a mini from the Warriors continuum. Mini-monsters are sentient, non-speaking toy cars of various makes, models, and colors, and each car has the misspelling responsible for spawning it written on its sides.

Dissimilarly to some minis, mini-monsters prefer two thimble-fulls of oil a day over bacon and eggs.

Canon Origin
Since the main characters of Warriors are cats, they see human vehicles as big, scary monsters. To the Clan cats, the monsters appear to swallow Twolegs, go to sleep when they park, and have a loud call that sounds before the monster arrives. The monsters move at such high speeds that they are very dangerous to cats; several main characters have been killed by monsters in the series. However, the cats have also figured out that monsters are strangely fearful of leaving the black Thunderpaths they seem to live on, and can usually be avoided simply by staying off the road.