A flying frog that changes colors, a stick insect that’s a foot and a half long, and a “ninja slug” that shoots “love darts.” These are among the 120 new species discovered or described over the past three years on the lush island of Borneo–the Southeast Asia island divided between Malaysia, Indonesia, and Brunei.

On Earth Day, the conservation group WWF released a report on some of the recent discoveries in a 54-million-acre nature preserve known as the Heart of Borneo. WWF ecologist Adam Tomasek says that on an average, three new species were found every month.

Teenage Mutant Ninja Slugs?

This colorful green and yellow slug species, named Ibycus rachelae, was discovered atop high mountains in the Malaysian section of Borneo. The slug has a tail three times the length of its head, and it wraps the tail around itself when it is resting. From the Ariophantidae family, this unusual species makes use of so-called ‘love darts’ in courtship. Made of calcium carbonate, the love dart is harpoon-like which pierces and injects a hormone into a mate, and may play a role in increasing the chances of reproduction [Guardian].

Image: Peter Koomen / WWF