9 Headed Monster as Mt. Meru

The Rudra also showed supernatural powers, for he transformed himself into a nine-headed monster huge as Mount Meru, with eighteen hands -- he was after all, a bodhisattva of the eighth degree who had fallen back. So it was that even the Buddhas found it difficult to subdue him, not to mention the gods and humans! http://www.khandro.net/deity_tale_of_two.htm