4x12 - Tales from the Crypt

An aging puppeteer gets a new assistant. When he learns that his wife has a boyfriend, the assistant promises he'll do something about it. The puppeteer spends most of his time with is favorite puppet Koko. When he discovers that his assistant is his wife's lover, the two make him think that Koko has gone on a murderous rampage. Little do they know that Pinocchio isn't the only one with-out strings.