- Order: Saurischia
- Suborder: Bird Feet
- Infraorder: Bird Wyvern
- Superfamily: Eared Bird Wyvern
- Family: Kut-Ku
A member of the Bird Wyvern family, Yian Kut-Ku is easily one of the most recognizable of all bird wyverns due to its somewhat comical appearance. These Bird Wyverns have lightweight frames, hollow bones, and typically have large beaks. They are very fast on ground, and competent fliers in the air. Yian Kut-Ku closely resembles and shares its superfamily with its cousin, Yian Garuga. The Bird Wyvern is often described to run and peck like a chicken and look somewhat like a parrot.
The known Old World habitats of the Yian Kut-Ku consists of the Jungle, Forest and Hills, Swamp, Tide Island, Everwood, Hermit Forest, Jurassic Frontier and Old Volcano (albeit rarely). The creatures favour these areas for their warm climates and abundance of food. Kut-Ku can also rarely be found in the Old Volcano in order to possibly eat coal and other ingridients to supply their flame sac with.
Yian Kut-Ku are omnivorous creatures that eat a wide variety of different things. Kut-Ku will eat lots of insects, such as Konchu, nuts and honey. While they are fully capable of defending themselves against smaller predators such as Velocidrome and their packs Kut-Ku are often preyed upon by larger predators like Rathian, Abiorugu, Najarala and Pariapuria. Kut-Ku are well known for getting into territorial conflicts with the extremely agressive Yian Garuga. Sometimes a Garuga will take over a Kut-Ku's territory and even kill the smaller bird wyvern. Female Yian Garuga will also destroy the eggs of a Kut-Ku and lay their own eggs in the nest, leaving the Kut-Ku as a victim of brood parasitism.
The average size of an adult Yian Kut-Ku is approximately 898.6cm. Yian Kut-Ku are capable of flight, which is a major advantage when fleeing from large terrestrial predators. However, they aren't as adept in the air when compared to other wyverns. Due to this Kut-Ku spend more time on land. The Yian Kut-Ku can hurl large fireballs, and, although these are effective at killing weaker prey and predators, they have little effect against larger and more powerful predators. Kut-Ku have very large and sturdy beaks used to crush hard-shelled prey and fruit, as well as aid them in shoveling up ground-dwelling insects and larvae. This is particularly visible when it is feeding on Konchus, as it can bypass their hard shells by simply scooping the Neopterons up when they roll into balls and swallowing them whole.
The most defining trait of Yian Kut-Ku are their specialized large ears. These ears are very sensitive to sound and sudden loud noises can disorient them leaving them vulnerable to attack, thus causing hunters to often use Sonic Bombs when hunting these creatures. Some rare individuals, most likely elder Kut-ku, are seen with larger ears, larger muscles, and a more developed flame sac that is able to make short lived walls of fire, making this elder Kut-ku even stronger than a Yian Garuga.
During breeding season female Yian Kut-Ku grow feathers on their abdomen. These feathers are used to keep their eggs warm. These feathers can also be considered a remnant of their ancestors.
Yian Kut-Ku of the Barubare region have four toes while their other counterparts have only three. This is thought to be a recent mutation of some sort, although the "four-toe" variant of Kut-Ku has sporadically appeared in the Verdant Hills as well.
A somewhat temperamental, skittish, and inquisitive wyvern. Yian Kut-Ku have a tendency to want to appear bigger than they really are by spreading their wings, flaring out their ears, and shriek out a loud squawking roar. The Bird Wyverns hope that this show of bravado will discourage predators but if it fails Kut-Ku will immediately flee the area. Though some individuals are more powerful than they appear as they age. During the breeding season female Yian Kut-Ku grow feathers on their abdomen and use them to keep their nests of eggs warm. After the eggs hatch and Yian Kut-Ku chicks are born the mother watches over them and feeding them honey and insects till they reach a certain age.
Depending on the weather during the year, Yian Kut-Ku will breed all year round.