Stella Star (The Adventures of Willy Nilly and Thumper Series #3)

Willy Nilly and Thumper are best friends and adventurers with a knack for getting into tight squeezes and out of sticky situations, and always, always doing the right thing. When Thumper wishes on a star and that wish comes true, he and Willy Nilly make an exciting new friend named Stella but soon realize that she belongs in sky. All three of them have to use their wits to get her home before nightfall. But can they outsmart a wicked witch who wants to stop them?