Mine is a dragon, a secret agent, and maybe an ant. That's coz i'm still learning, but when i master it i'll transform myself into.... Sora, Cloud, Sephiroth, Zero, Nobunaga Oda, Hanzo Hattori, Sun Ce, Lu Bu, my other self (let's call it a half-dark half-light blue-haired man with half dark half white wings - you get the idea - with a sword-whip in the left hand and a rod-nunchaku in the right hand - and don't forget the dark purple eyes and the mecha-arms and legs) and other things I remember later (whoa what a long list).

Got this idea while reading another topic, so what's your favorite form/transformation in a dream?