Monstrous Maud: Freaky Sleepover by A.B. Saddlewick (author) (UK edition)

When Maud’s perfect twin sister, Milly plans a sleepover, Mum forces Maud to have her friends over too. What can possibly go wrong? Nothing much … just that Maud’s mum might find out about Rotwood High being a school for real monsters! As if that’s not enough to worry about, Maud is tricked into looking after Violet, the school hamster, by her arch enemy, Poisonous Penelope. But Violet is no ordinary hamster! She’s a pedigree vampster and an expert cage-breaker. With a vampster on the loose, sleep is the very last thing that happens! Another terrifyingly terrific tale in the Monstrous Maud series, written by A.B. Saddlewick.