Grimmsnarl (Japanese: オーロンゲ Ohlonge) is a dual-type Dark/Fairy Pokémon introduced in Generation VIII.
It evolves from Morgrem starting at level 42. It is the final form of Impidimp.Grimmsnarl has a Gigantamax form.

Grimmsnarl is a green-skinned humanoid Pokémon with most of its body covered in dark purple hair, except part of its face, its abdomen, its feet and a small red patch on its chest. Like its pre-evolutions, Grimmsnarl has large crescent-shaped ears with red insides, albeit they are longer on this form. Its long, sharp nose points upward and has a single long red nostril. It has a blue tongue and six teeth protruding from its mouth, the front four of which are flat, two on each jaw, while its upper jaw also has one sharp fang on each side. It has white eyes with red irises and black pupils, and grey eyelids. Its face ends in a small pointy chin.

Grimmsnarl's hands and feet have three pointed digits each. Most of its long hair wraps around its body, except for a lock on each side of its face, a few spikes raised on its shoulders and some locks draping from behind its legs resembling a cape. While being bulkier than its pre-evolutions, Grimmsnarl is more slender than it appears to be, with its hair giving the appearance of a muscular body. It is a male-only species.Grimmsnarl,Hatterene,and their evolutionary families can be considered counterparts.

Both are Generation VIII Pokémon evolving once at level 32 then at level 42.
Grimmsnarl and its pre-evolved forms are male only, while Hatterene and its pre-evolved forms are female only.
Their final evolved forms are both Fairy-type Pokémon with identical base experience and catch rates.
Each Pokémon in each evolutionary line have the same base stat total as their counterpart (e.g. Grimmsnarl and Hatterene both have a base stat total of 510).
Both Pokémon also have a Gigantamax form, a signature G-Max move, and use their body hair as their primary weapon.
In addition, both Pokémon are based on mythical beings from European folklore and mythology: Grimmsnarl resembles trolls, ogres, and goblins and Hatterene resembles witches.
Lastly, both are the signature Pokémon of two of the rivals in Pokémon Sword and Shield, Marnie with Grimmsnarl and Bede with Hatterene.

Until now,no other Pokémon have the same type combination as Grimmsnarl and its pre-evolved forms.
(The above content is from the bulbapedia.)