How about a stick insect species in which the female has horns? Meet the Annam Stick Insect. Adult males are just boring with a smooth skin and thin body. But the females, no! They look like they are made of wood and have two funny horns at the top of their head.

You can read all about this species and how to keep it as a pet on the Annam Stick Insect page.

Adult female Annam Stick Insect