Haxorus is a bipedal Pokémon with a dark, yellow-green covering on its back and most of the front. It has black skin covering its torso, tail tip, and thighs, as well as red talons and claws. Its large tusks, which resemble scythes, are black and edged in red, and are located on its upper jaw on the side of its mouth. Its medium-sized eyes are red with black pupils. Ridged plate-like skin travels from its back to its head region. It has solid armor and the legs and tail have a dividing line pattern. Its arms are quite small, with three digits two elliptical triceps and biceps, and circular elbows. Its hands are small and circular with small red claws. Its legs are formidable and strong with three-toed feet with a red talon on each toe.
Haxorus takes great pride and joy in its prized, unbreakable tusks, which are used on its enemies and can cut through steel beams and metal transmission towers with ease. Despite its austere appearance, it is generally friendly. However, Haxorus is known to be very territorial, and it will react violently should anyone touch its tusks. Haxorus is known to reside in caves and abandoned mines. Haxorus has a diet of eating the minerals in the dirt to keep its tusks sharp.
According to Junichi Masuda, Haxorus was the first Pokémon to be designed for Pokémon Black and White.Ken Sugimori further clarified this in an interview with Nintendo Dream, stating that Haxorus was designed while Pokémon Platinum was still in development, at a time when the development of Pokémon Black and White had barely even started, by a newly-hired female designer. Haxorus's pre-evolved forms were designed later, based on its design.
Haxorus is based on dinosaurs. The design came from the idea of a Pokémon that swings its axe-like fangs to attack instead of biting, a behavior reportedly stemming from actual dinosaurs. The specific dinosaur may be the Dicynodonts, tusked synapsids with thick hides from the Permian era, most likely Placerias. Haxorus's tusks in particular resemble battle axe blades.
Haxorus may be a combination of hack (to chop or cut down), axe, -saurus (common suffix in names of dinosaurs and extinct reptiles derived from the Ancient Greek word for lizard), and possibly hazardous.
Ononokus may be a combination of 斧 ono (axe), 戦く ononoku (to tremble), アックス akkusu (axe), and possibly -onychus (common suffix in dinosaur names derived from the Ancient Greek word for claw).
In other languages
From 斧 ono, 戦く ononoku, axe, and possibly -onychus