An evil muppet possessed by the spirit of the devil that goes on a rampage attempting to kill all good muppets and their creator, GOD.
"Stop trying to kill me you nefarious muppet!"
by Archibald Wednesday January 1, 2005
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Someone without intelligence who tries to make up for it by turning to the devil.

Usually from Plymouth.
"Get away from me you spawn of satan. What are you, a nefarious muppet?!?!?"
by Sexy Bint January 1, 2005
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