Rathalos is a non-playable boss character in the fighting video game, M.U.G.E.N Trilogy. They are a type of flying wyvern from the Monster Hunter series, created by Capcom. Rathalos and the other bosses were confirmed on July 4, 2018 and are one of the most well-known monsters in the series, and can appear in many varied habitats.
Rathalos is a recurring monster from the Monster Hunter series, and the flagship monster for the original Monster Hunter; it is sometimes known by its epithet "King of the Skies" and belongs to the Flying Wyvern family of monsters. In addition to its female counterpart Rathian, there are a number of Rathalos subspecies in existence, such as Azure Rathalos. Its description in Monster Hunter World states that "Rathalos descends upon invaders from the sky, attacking with poison claws and fiery breath", which is reflected accordingly in its attacks in Super Smash Bros. Ultimate.
Armor, in both Blademaster and Gunner variants, can be created from materials procured from hunting Rathalos in its home series.