We did a Scooby Party for my son's 3rd birthday. A few of the games we played were Hot Scooby (hot potato only with a stuffed scooby). Clothes pin drop except we used dog biscuits-- children try dropping clothes pins/dog biscuits into a jar, the one with the most wins. Pin the scooby snack closest to scooby's mouth. We did a scooby pinata and the kids took home their candy in a "doggie bag". Also, you could find inexpensive dog dishes for the kids to eat their cake out of.