Jackson’s Chameleons are charismatic lizards that are popular in the pet trade due to a number of unique features, including color change ability, tongue strike feeding, and horns in males. Although chameleon horns are thought to function as ornaments and weapons, the underlying biology and genetics remain uncharacterized. We will examine the genetic and functional bases of horn development and use in Jackson’s chameleons via DNA sequencing and behavioral contest trials in males.