Macavity is the Mystery Cat. He's ginger-colored, tall, and thin. He is the leader of the strays, a group of cats who generally cause havoc amoungst the Jellicles and people about town. He is a criminal mastermind; that is how he earned one of his many nicknames: the Napoleon of Crime. He's also called The Hidden Paw because when you reach the scene of crime, Macavity's not there!

During the Jellicle Ball, Macavity and his henchrats kidnap Old Deuteronomy, the leader of the Jellicles. All the Jellicle males run off to help track down the mystery cat. Meanwhile, Bombalurina and Demeter explain to the younger cats and kittens about Macavity and his exploits. Then the toms return and so does Macavity - except he also returns Old Deuteronomy. The Jellicles are reunited with their leader, but Demeter senses something odd and jumps on Old Deuteronomy, revealing Macavity! Munkustrap and Macavity then fight. Munkustrap is wounded and retreats to the side. The other toms take their turns fighting the Hidden Paw. Macavity knows he cannot win single-handedly against the entire Jellicle Tribe, so he grabs two spark plugs. Touching them together, he plunges the Junkyard into darkness.

"For when you reach the scene of crime, Macavity's not there!"