The Abomination was a creation and masterpiece of Giuseppe di Cattivo. He painted it with pigments made from sentient rock that fell to Earth. The Abomination drove di Cattivo insane. He crafted the Chinese Puzzle Box to make sure no one ever saw it.
The painting was stored underneath the International Gallery and recovered by its sister, Mona Lisa. It was shot and killed when K9 destroyed the painting's pigments and then the living Abomination. It took the form of a huge Demon. (TV: Mona Lisa's Revenge)