Caleb is a kitten with grey, pearl bush colored fur. On the top of his head, there are two small tufts of fur. His nose and the inside of his ears are pink while the underside of his back paws both have light pink pads. He has a line between his nose and mouth which is known as a philtrum, and he appears to have fangs. He has a missing bit in his left ear and a spot of darker colored fur over his left eye. On each side of his face there are two whiskers that protrude from each cheek.
Caleb wears brown pants and a green, long-sleeved shirt with yellow accents. He also has a bandage wrapped around his tail.
In the original version of True Tail, Caleb was an orphan and the squire of Brutus Ironclaw.