Luigi has a nervous, timid personality unlike his brother Mario. On the SMB Plumbing website's ' Questions,
," it is mentioned that Luigi also cries in fear by the time the brothers were creating the FAQ. In the climax of the movie, he becomes more confident, as he stands up to Bowser by shielding his attack that he was about to scorch Mario with, before using a star to plow down his army.

Luigi is tall, wears a green hat and matching shirt with blue overalls and brown boots. He has a mustache.