Rathalos aka 'Kings of the Skies' 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 their feet are highly poisonous and are known to 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 highly territorial monsters, and as such, are aggressive towards intruders. An adept flyer, Rathalos often use fire-balls to attack foes from both land and air. Rathalos are able produce these fireballs due to it having multiple flame sacs. Rathalos have powerful hind legs, making them fast on the ground, as well as giving them the capability to launch devastating claw attacks from the air, often severely injuring its target. While in the air, they are also capable of diving to claw foes on the ground. A Rathalos' claws contain a potent toxin used to injure and sap the preys strength. Rathalos, like many others of its kind, have a powerful roar that they use to intimidate rivals and stun prey.
Like most true flying wyverns, Rathalos possesses the cunning, speed, and strength to fell almost any threat or prey they come across in the wild though they will rarely challenge anything larger than themselves outside of their territory. Rathalos are especially aggressive during mating season. After mating with a Rathian, Rathalos will patrol his territory from the skies, looking for any threats to attack and eliminate from the his territory.