5. Duskull
What is it: Duskull is a Ghost type Pokémon who is native to the Hoenn and Sinnoh regions and crops up in Johto's Safari Zone too. It's known as the Requiem Pokémon and is able to levitate and avoid any ground moves.
Why is it creepy: Well, it evolves into Dusclops which is known as the Beckon Pokémon, and then Dusknoir which is known as the Gripper Pokémon. It evolves into Dusknoir with the help of an item called the "Reaper Cloth", suggesting Dusknoir to be a Grim Reaper, so Duskull is essentially a baby Grim Reaper waiting to grow up. That's not all though. From various Pokédex entries, it is stated that Duskull can pass through walls and loves the crying of children and it is said that if it finds bad children who don't listen to their mothers, it will spirit them away. Another Ghost Pokémon who kidnaps children.