Koopeleons are a rare and unique sub-species of Koopa that live in the Toadwood Forest in Mario & Luigi: Partners in Time. In fact, Koopeleons are so distinct from their Koopa ancestors that the two may actually be separate species altogether. Regardless, a Koopeleon resembles a Koopa-chameleon hybrid with a blue shell, green skin, large eyes, and a long curled tail. Koopeleons have the ability to turn invisible, a survival mechanism that allows them to hunt unsuspecting prey. However, experienced travelers know they can track an invisible Koopeleon by the dust it sends flying in the air when it moves. To attack, a Koopeleon will run into its foe, delivering damage. This attack can be dodged and countered with a jump attack. Fortunately, if damaged, a Koopeleon will become visible.
Koopelon have their own sub-species, called Gold Koopeleon.