That sounds like something from Crank Yankers, except not as funny.
You shouldn't take that job. Too risky, he might be some sort of predator/serial killer. Whatever it was, he was clearly psychologically disturbed. If he really did have his mother there it sounds like somebody should do something about his situation. If there was a mother there she wasn't a very good mother if she was making him make a call like that. Call the police if you receive another call from him.
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I will befriend the friendless, help the helpless, and defeat... the feetless?