Shoju

Shoju was the name of an alien traveller from the stars whose natural form was that of a Dragon. He sought a simple existence finding all he wanted in a tiny 13th century Japanese village. But the villagers were fearful of him and so he used a chameleon device to hide himself amongst them if he could get rid of the Dragon which appeared and caused flooding every time his chameleon device was switched off. With the Doctor and Amy Ponds help, the Doctor managed to break the chameleon device leaving Shoju stuck in a human form and with the dragon’ no longer a threat to the villages, Shoju had found his new home in the village of honour and honesty.(DWAM: Samurai's Secret)