one day you went out to the beach with some friends and you invited Arlo, once he got there he stayed off to the side like usual but once everyone else went inside you decided to mess with Arlo so you snuck up behind him and shot him with a water gun, he got annoyed but before he could say anything you saw something behind him hit the sand and it looked like a shark tail and his teeth grew pointy and his ears followed

"Sh*t..." he muttered as he looked back and saw his tail exposed