Nephew Birthday

My nephew is turning 6 tomorrow.  I barely ever get to see him because my brother only has him every other weekend.  Anyhow, we do get to see him for his birthday.  My brother actually gets him from 8am-8pm.  Does anybody have any ideas what I could get him around $20????  He is just a regular 6 year old boy, but I am clueless!!!!!  Here is a picture of him that might help: