Most Wanted: Son of Slappy by R.L. Stine
The evil puppet you hate to love is back for a brand new scare. Jackson Stander is every parent's dream. He doesn't get into trouble, he always does his homework, and he never, ever lies. His teachers all trust him completely. He even volunteers at the local Youth Center. But that was all before Jackson came across an evil ventriloquist dummy. Now he must deal with Slappy wreaking havoc on his family and friends. Jackson will soon see that two Slappy's are not better than one!