Known as the "Thunder Wyvern." Astalos can charge itself with furious movements of its wings, tail and crest. In its charged state, the membrane in its wings take on a beautiful glow that only barely offsets the terrible nature of this monster.
- Order: Saurischia
- Suborder: Wyvern Feet
- Infraorder: Electric Wing Wyvern
- Superfamily: Electric Wyvern
- Family: Zekusu
Astalos are high up in the food chain. They are known to be predators and have been found to feed on Herbivore like Mosswine and Aptonoth. Astalos have also been observed eating Neopteron like Vespoid and lesser predators like Velocidrome. Despite being top predators, Astalos have to compete with other large predatory monsters like Rathalos, Najarala, Seregios, and Seltas Queen. It also has to compete with rare, powerful monsters like Rajang, Deviljho, and Elder Dragons.
Astalos's whole body is an electrical organ. Astalos uses Piezoelectricity — as an Astalos fights and becomes more active, certain body parts will begin to charge up with electricity quickly. Its tail, wings, and crest are the only parts of its body that will become electrically charged. This can easily be seen by looking for green surges of electricity on those parts of its body. The more charged up it is, the more range and power its electrical attacks have. Throughout the Astalos's whole body is a razor-sharp shell covered in spikes. This shell can easily cut up prey with just a single touch. Astalos's flying abilities are comparable to a Rathalos with the help of its powerful wings. Its wings are tough, covered in spikes, and are even used as weapons on the ground. The wings can also produce a special electrical charge used for capturing prey. Its pincer-like tail is used for capturing and paralyzing prey.
Astalos are extremely aggressive Flying Wyverns known for their brutality and for attacking everything. Astalos are known to usually be the ones that start the fight in their territory. They've been seen attacking large Flying Wyverns, like Rathalos, even if those monsters are not interested in the Astalos's presence. Even if the enemy is losing the fight, Astalos will fight them relentlessly, even if they are trying to escape. If the enemy is killed, the Astalos may feed on the enemy's corpse, as it is sometimes known to do. Astalos will even sometimes cannibalize their own young by accident. This is due to the adults mistaking the young for Neopteron like Vespoid occasionally. To prevent this, Astalos guard their nest up until the eggs are ready to hatch before leaving the young to fend for themselves. Even while young, Astalos don't hesitate about anything, including cannibalism, and can be quite violent. When the Hunter's Guild gets reports of this monster, they are known to send hunters immediately to hunt it down. This is due to Astalos actually disrupting the ecological balance in an area.