Mr. Cottonhorn is Dexter Charming's jackalope companion. Appearance-wise, he is a rabbit with antlers. He normally wears black-rimmed glasses, much like Dexter's. He is described to be an incredibly intelligent animal and has mastered mathematics.
- March 19, 2013: Mattel requests the trademark for Mr. Cottonhorn.
- October 08, 2013: Mr. Cottonhorn makes his book debut in The Storybook of Legends.
- "Cottonhorn" is a pun on the usual rabbit phrase "cottontail".