My Pet Monster Movie (1986)

a boy named Max (Sunny Besen Thrasher) and his sister Melanie (Alyson Court) go to a museum with some kids during a school field trip and see a monster-like statue that Dr. Snyder (Colin Fox) had brought back from the Middle East. After being exposed to the statue and sunlight simultaneously, Max finds himself turning into a furry blue monster whenever he gets hungry. Dr. Snyder tries to hold him captive, but Max escapes and eludes him.