Rathalos (Japanese: Rioreusu) is a medium-sized wyvern that is usually spotted in the Forest & Hills area. Frequently referred to as "Los" by players, he is a favorite of both veteran and beginner hunters alike. Rathalos is aggressive, and will attack any hunter on sight. His attack pattern varies from flying to charging at the hunter on the ground. He is also regarded as "King of the Skies" amongst the Guild and Village members, hence Rathalos prefers to attack the hunter from while hovering or in flight, rather than from the ground.
Rathalos is the male counterpart of Rathian
, whom contrary to Rathalos, prefers to attack on the ground, hence her nickname "Queen of the Earth". He is the "Heaven" in "Heaven and Earth" in numerous Monster Hunter quests and references, where "Earth" is Rathian
, simply because of their preferred attack methods.
There have been some hiccups in the translations from the Japanese to North American Monster Hunter releases. In some Guild Quests and movies, Rathalos is referred to as "King of the Earth", rather than "King of the Skies", where the title "Earth" belongs to Rathian
. Also, Rathian recieves the title "Queen of the Skies". It appears that in those quests and movies that Rathalos and Rathian have switched places, and apparently genders.