A Rathalos appears in ''[[Super Smash Bros. Ultimate]]'', both as an [[Assist Trophy]] and as a boss in both Classic Mode and the World of Light, the first to appear as both. ItHe is one of the few third-party Assist Trophies without any playable fighters from their home series, with the others being [[Assist Trophy#Akira|Akira]], [[Bomberman]], and [[Assist Trophy#Shovel Knight|Shovel Knight]].
As an Assist Trophy, ithe can strike the opponent with itshis claws or breathe fire onto the stage. When ithe roars, nearby fighters may be stunned. In the boss fight for Rathalos, the player fights ithim on a flat plains stage resembling the [https://monsterhunter.fandom.com/wiki/Ancestral_Steppe Ancestral Steppe] from the ''Monster Hunter'' series. ItHe is fought in the final round in the Classic Mode routes for [[Yoshi]], [[Marth]], [[Duck Hunt]], and [[Piranha Plant]]. ItHe is also fought in the Classic Mode route for [[Bowser]] and [[Hero]], albeit before the final round (with [[Mario]] and [[Metal Mario]] for the final battle for Bowser, and with [[Robin]] and a giant [[Charizard]] for the final battle for Hero).
