Night of the Living Dummy by R.L. Stine
They're baa-ack! Make way for the bestselling children's series of all time! With a fresh new look, GOOSEBUMPS is set to scare a whole new generation of kids. So reader beware--you're in for a scare! Kris's twin sister has just gotten a ventriloquist's dummy and it's all anyone - their parents, their friends - seem to care about. Kris is tired of being ignored so she gets a dummy of her own. But double the dummies start to mean double the trouble...and horror.