Source: http://monsterhunter.wikia.com/wiki/Rathalos

Rathalos are Flying Wyverns introduced in Monster Hunter.

Rathalos are large, bipedal wyverns with a spiny, armored hide covering their body. Their outer shell features much brighter and more vibrant colors than that of their female counterpart, the Rathian. It is primarily bright red, with black markings throughout. Like the Rathian, Rathalos possess a flame sac which is used to produce deadly flaming projectiles from the mouth. The talons upon a their feet are highly poisonous and are known to inflict toxic mortal wounds on larger prey. In addition, their long, thick tail features a heavy spiked club at the end. Rathalos' wing membranes feature ornate patterns which are likely used to attract potential mates.

Rathalos are expert flyers, and as such are prone to hunting from the skies. By launching a surprise aerial attack, they can inflict poisonous wounds with their talons or burn prey with flaming projectiles. On the ground, Rathalos remain formidable opponents. Using their powerful legs, they can chase down prey from a distance or inflict blunt-force damage with their clubbed tail. At a close enough range, they are known to use their sharp teeth to bite at foes as well.

Rathalos are highly territorial monsters, and as such, are aggressive towards intruders. They will chase away or attempt to kill any monster which may pose a threat to their land. While hunting, Rathalos will stalk prey from the air before swooping in for the kill. Once they have successfully brought down their prey, they will carry it away to eat in private, safe from scavengers or other large monsters which might attempt to steal the kill.

Rathalos have been spotted in many kinds of environments, from the temperate Forest and Hills to the extreme heat of the Volcano. As a master of flight, they will travel far and wide, searching for prey from the skies.