Charlie's Monsters (Nightmare Academy, Book 1) by Dean Lorey
Hogwarts meets Men in Black in a thrilling comic adventure about a very gifted boy who joins a monster fighting academy.
Charlie Benjamin is not like other children - when he sleeps he has terrible nightmares, and when he wakes it is to find his room has been wrecked. Then one day he wakes up to find a monster by his bed. Luckily, a band of monster-hunting strangers arrives and saves him, only to whisk him away for interrogation by the mysterious Nightmare Division.
It turns out that Charlie has the Gift - a rare ability to open portals into the dimension where monsters lurk, and the explanation for the devastating force of his nightmares. But his gift makes him a danger to himself and others: when he is made to open a portal his power is so great that he inadvertently wakes Barakkas, one of the most powerful and evil of all monsters.
Threatened with Reduction (a lobotomy that would remove his imagination) Charlie is saved by the wise Headmaster of the Nightmare Academy, where he is taken to explore his talents - and prepare for the coming showdown with Barakkas...