Possible Clues:

• Similarly named rival of a video game plumber
• Nintendo antagonist in purple overalls
• Nintendo bad guy with an inverted hat logo
• Zigzag-mustached Nintendo bad guy
• Nintendo villain
• Nintendo antagonist with a "W" on his cap
• Nintendo antihero with a zigzag mustache
• Nintendo villain in purple overalls
• Nintendo villain with an upside-down "M" on his cap
• Nintendo antagonist with a 'W' on his cap