Evil fairy Maleficent had the ability to turn into a large, black and purple, firebreathing dragon. This she did first to try to kill Prince Philipp; however, Philipp, thanks to the help of the Three Good Fairies, was able to vanquish the beast; upon her death, Maleficent turned back into her normal form.
When Maleficent was revived two years later by her raven Diablo, she petrified the entire castle, but Prince Philipp was able to escape. Maleficent turned once again into a dragon, but, even though Philipp had no sword to battle her with this time, and no fairies by his side, Maleficent accidentally injured herself and was forced to retreat.
Maleficent used her dragon form several times thereafter, including to battle Mickey Mouse.