Rathian aka "Queen of the Lands" is a medium-sized true flying wyvern similar in looks to her male counterpart, Rathalos. Her hide is a dull, muted green in contrast to the Rathalos's deep red, and her lower mandible features a long, protruding chin spike. Her upper back and wingtips are covered in a moss-like fur not seen on the Rathalos, and while her clubbed tail lacks bony spikes, it makes up for this with its ability to poison foes upon contact.
Rathian have a poisonous tail, but lack the poisonous claws of the male wyvern. They instead have developed poisonous barbs that deter most attackers. The roar of a Rathian is just as fierce as that of a Rathalos and its land-based maneuverability is even greater. Both Rathian and Rathalos have a spike protruding from their chin, but it grows much larger and sharper on Rathian, making their tackle attack even more dangerous for wyverns and hunters alike. Rathian have the ability to perform backflips to knock a foe out of its way while simultaneously poisoning them. Even if a hunter was to sever a Rathian's tail, her backflip attack would still poison the hunter, suggesting that the poison-producing organ is near the base of the tail or near the flame organ.
Rathians are very territorial, choosing to patrol from ground while her male counterpart patrols from the sky. It will become very aggressive to potential threats, especially when it is taking care of its young.