Yadoking "Slowking"

About

Slowking is a bipedal Pokémon with a Shellder latched onto its head. It is primarily pink, with a pale yellow muzzle and scaled belly. Its feet and hands each have a single clawed digit, while the hands also have a clawless thumb. Around its neck is a spiny ruff with alternating red and white stripes. The Shellder on its head has a spiral shape with two horns near the base. A red gem resides in the center of the Shellder. The Shellder's eyes are visible on the back of the Shellder.

Shellder's bite releases venom into Slowpoke's brain, causing a chemical chain-reaction that unlocks a superior intelligence and extraordinary power. More venom is injected into Slowking every time it yawns. The more venom the Shellder releases, the more intelligent Slowking will become. However, if the Shellder on its head comes off, it will forget everything it has learned and would revert itself back to Slowpoke. Slowking's intelligence can match that of a human and it constantly attempts to learn more. Its inspiration and intuition are also highly developed, and Slowking is able to stay calm in any situation and plan situations with effective results; this allows Slowking to solve anything. In the games, Slowking's speech is said to be unintelligible; however, in the anime, it can understand and speak the human language.

According to The Complete Pokémon Pocket Guide, it has such an easygoing personality that it is never stressed. Slowking is rarely found in the wild, though it can be found by the water's edge. It has been seen eating seaweed and drinking coconut milk. In Alola, it is known as "the sage of the sea", and it occasionally matches wits with Oranguru by the beach.

Forms
Slowking has a regional form: Galarian Slowking.

In Galar, Shellder's bite causes a different chemical reaction in the brain due to the Galarica spices that make up Galarian Slowpoke's diet, causing Galarian Slowking to take on a unique appearance. The tip of its tail and the top half of its body is purple, and it has a long dark cloak that drapes from its neck. The Shellder has grown more dominant, appearing completely different with a rougher texture, a darker gray coloration and a larger size, covering Slowking's eyes and nostrils. It has several purple spots dotting it, with a large one at the center that surrounds a green gem and two black eyes. The spikes on the Shellder are more blunt, and it has two purple horn-like tubes on either side from which poison may be secreted. The Shellder's teeth have also grown in size and are broad and flat instead of sharp; the same holds true for its wearer.

As Galarian Slowking evolves, the Shellder on its head has its intelligence skyrocket, giving it the ability to control the Slowking, as well as psychic powers that can rival the power of other Psychic-type Pokémon. Galarian Slowking have been observed chanting mysterious spells and incantations in battle or to communicate with each other. It also chants these spells while creating strange potions using its internal toxins. What these incantations and spells mean have yet to be fully understood.

Evolution
Slowking evolves from Slowpoke and is one of its final forms, the other being Slowbro.
Galarian Slowking evolves from Galarian Slowpoke. It is one of its final forms, the other being Galarian Slowbro.

(Source: Bulbapedia)