Most Pseudo Wyvern in Monster Hunter are similar to cats in behavior, while their appearance is more reptilian. Because their wings are mostly used as legs, the muscles controlling their flight seem to be weaker and smaller than they are in Flying Wyvern. For this reason, most of them are weak fliers, with the exception of the Barioth. In Monster Hunter, the Pseudo Wyvern are more primitive than Flying Wyverns and among them are the ancestors of the Flying Wyvern. The ancestor of all Flying Wyverns is the Pseudo Wyvern Wyvernrex.
While the name was coined in regard to Monster Hunter, similar animals appear in many works of fiction. Examples are the Monstrous Nightmare from How to Train your Dragon or the movie-versions of the Hungarian Horntail from Harry Potter and Smaug from The Hobbit. For this reason, the term Pseudo Wyvern in this wiki is not only used for monsters from Monster Hunter.
A similar gait is also used by bats and some pterosaurs, but the azhdarchid pterosaurs have a much more upright posture, because the crawling gait of Monster Hunters Pseudo Wyvern uses much more energy. Many dragons from the Dragons of the World-Project, which tries to depict realistic and plausible dragons, also use a more upright gait like azhdarchids do.