The Abomination (Mona Lisa's Revenge)

The Abomination was a sentient rock that fell to Earth and was used as paint by Gussepi d'Cassi. The Abomination sent d'Cassi insane and he crafted the Chinese Puzzle Lock to make sure no one ever saw it. It was soon located underneath the International Gallery and recovered by his sister, Mona Lisa, but he was shot and killed by K-9. He took on the form of a huge Demon. (SJA: Mona Lisa's Revenge)