Kentauros

Kentauros is a quadruped, bovine Pokémon. It is covered in light brown fur with a thick, darker brown mane around the neck. It has a rounded muzzle with a dark brown nose, small, triangular eyes, three gray bumps running vertically down its forehead, and a pair of curved, gray horns grows from atop its head. Each of its three black tails has a tuft of fur on the end, and there is a single gray hoof on each foot. Kentauros is a male-only species with no female counterpart.

Kentauros is a violent, rowdy Pokémon that whips itself into a frenzy using its three tails. It serves as a warning to others that Kentauros is about to charge with astonishing speed. Once it starts charging, it is unable to stop or change course until it hits something. It lives and travels in herds on plains and grasslands. It will lock horns with others of its kind, and the herd's protector takes pride in its battle-scarred horns. While still ferocious, Kentauros are calmer in Alola than elsewhere, likely due to the region's climate. The practice of riding Kentauros is believed to have started in Alola. However, Kentauros in Galar are more volatile and don't want to be ridden.

(Source: Bulbapedia)