The Liars' and Fibbers' Academy

Think of a lie - double it - add a pinch of fibbing and a teaspoon of invention. Stir in a handful of clueless adults and a seemingly bonkers classmate, then sit back and wait for the pizza to rise. Danny Quinn isn't exactly lying when he announces that his sister has been reincarnated as a dog. No-one believes him though, so he is sent to The Liars' and Fibbers' Academy where he just learns to tell whoppers more convincingly. Aided by a girl who insists she's a mermaid named Derek, and Inigus Jowly, the school's mysterious caretaker, Danny is able to hoodwink his family until he finally learns the truth. But this turns out to be more outrageous than any fib he could come up with.