The M-60E3 is a general purpose machine gun and variant of the M-60 Series of machine guns. It was developed by Saco Defense in the United States. This variant was introduced as a lightweight and more updated variant to the weapon and possessed a foregrip.
Later on Luigi who was going to use it against the Koopa Empire with the others. This however didn't happen due to the fact that Luigi was incapable of walking and Mario wasn't able to carry him, leaving Luigi at Smash Club headquarters.