What is Nefarious Muppet?
1.
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?!?!?"
2.
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!"