I Am a Werewolf Cub

I am a werewolf cub (Jag är en varulvsunge) is a 1972 Swedish children's novel by Gunnel Linde illustrated by Hans Arnold. It was translated to English by Joan Tate.

Plot introduction
Ulf was bitten in his leg when stealing apples. He read the Book of Werewolves and understands he turns into a werewolf at full moon. His family notices that the previously timid Ulf is now talking back and sneaks out at night.