Frogspell

"Great fun!" – Diana Wynne Jones

Max Pendragon is probably the worst squire in King Arthur's kingdom – he is hopeless at sword fighting and frightened of horses. He would much rather train to be a wizard instead. So when he accidentally invents a spell that turns people into frogs, it seems his wish might come true.

But when Max goes to Castle Camelot for the Novices' Spell-Making Competition, events take an unexpected turn. He finds himself in league with Merlin against the scheming sorceress Morgana le Fay. There's no way his highly unpredictable Frogspell will be of any use. Or is there...?