I'm surprised nobody has yet pointed out the link with Punch and Judy (so I will). "Punchinello" is an intermediate form of "Punch", occasionally used in 18th and 19th Century Punch and Judy. It's thought that the name originally derived from "Pulchinello", one of the characters in the Italian "Commedia dell'arte".

There's a nice brief history of Punch and Judy here.

:-)
Ian