Lenny & Lucy — Philip C. Stead

Peter and his father are moving to a new house beyond the dark unfriendly woods. When they arrive at their new home, Peter wants to turn back. Fortunately, he has Harold for company, but Harold is just a dog and can't help Peter. Scared of the things hidden in the woods, Peter makes a tall pile of pillows. He stiches and sews. He pushes and pulls. And when he is done, he has Lenny, Guardian of the Bridge, to protect him and Harold.

Lenny is a good guard but Peter worries that Lenny will get lonely out by the woods all by himself, so he makes Lucy, who is a good friend. Together, Lenny, Lucy, Peter, and Harold discover that this new place isn't so scary after all.