Wizards of Waverly Place (2007)

S01E08 Curb Your Dragon

Justin discovers that his recently adopted beagle is, unbeknownst to him, a mystical dragon in disguise. Just when he starts to bond with his unusual pet, another person steps forward, asserting ownership of the "dog" and registering it for a nearby dog show. Justin must navigate this unexpected twist as he tries to prove his connection with the enchanting creature while preventing it from being taken away.