Name that NES game

ok this is a game i played in my childhood and cannot for the life of me remember the name. from what i remember, its a platformer where your a little kid, killing monsters? then you go around and get a "power up" pill and turn into like a gargoyle thing, with a baseball bat... i think..... i cant remember much more than that. i know its not much to go on but if anyone can remember that would be great.