Boo! Season 1 Episode 21 Park/Zoo ( Air Date ) Genre Animation category. Overview "Park - See if you can find Boo on the English Riverbank. Look out for a Plopping Water Vole, a Sliding Otter and a Gliding Swan! Zoo - See if you can find Boo as he hides at the Zoo. Look out for a Trumpeting Elephant, a Chattering Chimp and a Roaring Lion!".