Slowpoke

Slowpoke is a Pokemon that is downright difficult to understand. It is a dual Water/Psychic Pokemon, but most of the time, it seems like it doesn't know how to use its psychic moves. Slowpoke can be unpredictable as no one can read what it's thinking or even if it's thinking at all.

In the anime, it is revealed that Slowpoke can evolve if a shellder clamps on to its shell, enabling it to stand upright. However, if a Shellder clamps onto its head, it evolves into Slowking, in which it becomes super intelligent, even capable of human speech with ease.