Bedroom Theme

Me and my two year old son share a room right now due to me living with my parents. I am redecorating our whole room and I need help thinking of a cute theme that would go well for the whole room, I thought about just doing my sons side of the room a theme and mine another but I’d just like it to be one theme, I thought of Woodland Creatures but I can’t find really anything in that, well that’s not expensive as crap. Our room is going to be a charcoal gray.