Slappy Birthday to You (Slappy’s World #1) by R. L. Stine

Ian gets a dummy for his birthday from his dad. The dummy’s name is Slappy. It came with these weird words that makes it come alive. His cousin Vinny says the words. Then Slappy comes alive and breaks Ian’s sister’s doll and gets Ian in trouble. Vinny rips Slappy’s arm off.

~ Dillion S.