It undertakes research every day to solve the mysteries of the world. However, it apparently forgets everything if the Shellder on its head comes off.
(From Bulbapedia) 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.
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. 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. In the anime, it can understand and speak the human language. According to The Complete Pokémon Pocket Guide, it has such an easy-going personality that it is never stressed. Slowking lives by the water's edge. It has been seen eating seaweed and drinking coconut milk. In Alola, Slowking occasionally matches wits with Oranguru by the beach.
(From Bulbapedia)Slowking's shell makes it similar to hermit crabs, though it is physically similar to giant otters, giant salamanders, and hippopotamuses. Its shell "crown" may also be a reference to the mythical sazae-oni, a magical sea demon of Japanese folklore distinguished by its spiny "sazae" or "turban shaped" snail shell. It is also based on a king, as the growth around its neck is based on a king's ruff while its shell is similar to a crown.