Jade Leviathan

"Serpent of the deep, The Jade Leviathan is guard underwater citadels for eons to come. Legend has it that if encountered, they will change color, like a rainbow."

Appearance
The Jade Leviathan resembles a green, serpentine creature. It has a spiked ball on the end of their tail. They has a "whiskers" and a large, glowy grin.

Trivia

 * 'Jade' is based of a rock of the same name. Jade is an ornamental rock.