Purple-hatted Nintendo character

WALUIGI

["This lanky, mustachioed rival often appears in spin-off games but rarely gets his own spotlight."]

The clue refers to Waluigi, a well-known Nintendo character who wears a purple hat and is often seen as Luigi's mischievous counterpart. His name combines "Wario" and "Luigi," reflecting his role as a rival to both Mario and Luigi. The purple hat is a key visual trait that helps identify him in games like the Mario sports and party series.