Me, My Goat, and My Sister's Wedding — Stella Pevsner

Rudy the Troublemaker!
It starts out as lots of fun. Doug and his friends are delighted to goatsit for Rudy. They fix up their clubhouse, build a feeding trough, and fill it with goat fodder. But they have to keep Rudy a secret -- and that's not easy when Doug's family is always around, trying to plan his sister's wedding.

Rudy turns out to be a fine, playful goat, even if he does have a few bad habits. (Could Rudy be the mysterious white-bearded creature who peeks in windows at night?) And Rudy has a huge appetite. He'll eat anything...even wedding dresses!