It just came to my mind that it could be "Чертёнок" ("Чертёнок" is little чёрт) .
Чертёнок = Chertyonok

But "чёрт" (chyort) is not a Devil. It's a far lesser evil spirit (there are thousands of them). They are not necessary malicious, but often harm people because of boredom and inherent naughtiness. "Чертёнок" means the same as "imp" when applied to a child.

It was probably translated as "Devil" to simplify things.