I bought a couple of these for my two sons (3 &6years old). They both have a typical young boys toilet humour and love anything to do with gross bodily functions.
This small, cheap item kept them both occupied and laughing their heads off for ages, and they loved playing little practical jokes with them "oh no daddy's eating reindeer poo!". The only small niggle is that the sweets provided aren't great but you can replace those with a small sweety of choice - chocolate covered raisons were our personal favourite.
All in all a good cheap stocking / advent calender filler.