scaramouch
\ SKAR-uh-mouch, -moosh \, noun;
1.( lowercase ) a rascal or scamp.
2.a stock character in commedia dell'arte and farce who is a cowardly braggart, easily beaten and frightened.
Quotes:
…it seemed that the scaramouch in question had gained a wonderful ascendency over almost everybody in the Jeroboam.
-- Herman Melville, "Moby Dick ," 1851
That child—the scaramouch you picked out of the gutter at Valrosa—Toby—do you realize—have you grasped—the meaning of that yet?
-- Ethel M. Dell, "Charles Rex ," 1922
Origin:
Scaramouch entered English in the 1600s from the Italian scaramuccia literally meaning "skirmish." It is ultimately of Germanic orign.
Dictionary.com