The Luigi's Bulge meme stems from promotional materials for the 2018 Nintendo Switch game Mario Tennis Aces. Sharp-eyed fans on Twitter and Tumblr noticed that Luigi's character model featured a distinct anatomical protrusion in his shorts, leading to a viral obsession with the character's 'proportions.' The meme exploded as users performed mock-scientific measurements and created fan art, turning a minor design detail into a symbol of Nintendo's surprisingly detailed rendering. It is primarily used for shock humor, meta-commentary on video game design, and to highlight the unexpected 'alpha' energy of the traditionally timid younger Mario brother.