The Monsters of Morley Manor (sometimes subtitled A Madcap Adventure) is a children's fantasy/sci-fi/horror novel written by Bruce Coville, published in 2001.
It was originally serialized in Bruce Coville's series of short story anthologies.
They discover some small figurines of monsters (such as a werewolf, a medusa, and other familiar creatures) in an old abandoned house.
The boy and other children join them on a quest involving aliens, angels, and ghosts.
The book won a WMLA Sasquatch Reading Award.