There has been an announcement of a brand new mythical Pokemon for Ultra Sun and Ultra Moon. Zeraora, the Thunderclap Pokemon. This announcement comes from the Oha Suta show in Japan. Unlike most Electric-type Pokémon, it doesn’t have an organ within its body that can produce electricity. However, it is able to gather and store electricity from outside sources, then use it as its own electric energy. When it uses massive amounts of electricity, its fur stands on end all over its body.
— Ghost-type Pokémon (@Pokemon) April 9, 2018
Zeraora will debut in a major role in M21. Here is a further description of the Mythical Pokémon by Bulbapedia:
Zeraora is a bipedal feline Pokémon. It has gray underfur and yellow fur on its head, forearms, chest, hips, and upper legs. Blue fur can also be seen on its forehead, chest, and whiskers. Its eyes and paw-pads are similarly blue. Black zigzagging stripes can be seen on its thighs and forearms. It has four-fingered paws, while its feet have three toes each. A long, yellow, thunderbolt-shaped ponytail extends from the back of its head, giving the appearance of an actual tail.