2. Parasect
What is it: Parasect is the evolved form of Paras, and is a Grass/Bug type originally from the Kanto region. It is one of the many Pokémon associated with mushrooms.
Why is it creepy: Paras, its original form, has mushrooms called tochukaso growing on its back. The mushrooms and Paras actually exist in a symbiotic relationship, where Paras is the host and the mushrooms are parasites. When Paras becomes Parasect, the mushroom actually takes over as the host and controls the Pokémon. Parasect's dead looking eyes truly are dead eyes, as it is no longer capable of any sentient thought of its own, being controlled by the seemingly normal tochukaso mushroom. I imagine Parasect would warn its Paras children if the evil mushroom allowed it to speak.