There are 915 Pokémon in the Pokédex to date, most of which lean cutesy, but the scariest Pokémon are the Ghost-types, and of all these, there are five that are truly the most terrifying. Nintendo's beloved pocket monster franchise first debuted in 1996 in Japan, and the original Ghost-type Pokémon were Ghastly, Haunter, and Gengar. Now there are sixty Ghost-type Pokémon altogether, though only a handful can claim to be the scariest.
Ghost-type Pokémon are tied for second-rarest type with Fairy, Ice being the rarest type of all. Ghost-types are the only type with two immunities, as they are immune to both Fighting and Normal attacks, as well as to moves that prevent escape (Gen 6 and later). They are only resisted by Dark-types, and Ghost-type moves do not affect Normal-type Pokémon.
Most Pokémon are adorable, so even the majority of the Ghost-types appear relatively harmless. Only a few have truly frightening visages, and the five scariest Ghost-type Pokémon were ranked based on a priority order of: appearance, behavior and backstory, moves, and abilities (abilities were introduced in Gen 3 as a new game mechanic).
5. Sableye, The Spooky Ghost Pokémon That Haunts The Depths
Sableye is a Dark/Ghost-type Pokémon. Legends claim that they steal souls when their eyes glow, but these Pokémon are actually friendly, just mischievous and attention-seeking. However, their appearance and movements are jerky, puppet-like, and unnerving. Their heads twitch from side to side. They live in deep, dark caverns. They learn the moves Confuse Ray and Shadow Sneak, and have the abilities Stall and Prankster.
Sableye ranks in the top five mostly because of its appearance and the fact that it is found in darkness, but its moves and abilities only add to that. Confuse Ray is a perfectly frightening skill for any Pokémon to have; the afflicted are unable to discern reality to the point that they damage themselves. Then Stall and Prankster make this strange, unnerving Pokémon unpredictable, as Stall causes it to not move until the very last moment, and Prankster will re-prioritize a status ailment skill to hit out of the blue.
4. Ghost-Type Pokémon Trevenant Is A Grim Forest Guardian
Trevenant is a Grass/Ghost-type Pokémon. It is known to consume anyone who dares destroy the forest in which it lives, and curse or forever trap anyone who damages trees there. It doesn't normally attack anyone else, though. Trevenant is able to communicate with and control trees through a root-like nervous system, and when it dies, it becomes a normal tree. It learns the moves Confuse Ray, Destiny Bond, Curse, and Phantom Force. It does not have any scary abilities.
Trevenant ranks #4 because of its move, Destiny Bond, and the fact that this darkly-protective Pokémon is a dual-type. A fan theory about Ghost Pokémon suggests that Ghost-types were actually some other Pokémon who died; the move Destiny Bond only mentions fainting in-game, but assuming death is possible, that means a dual-type Ghost Pokémon could use this move to kill off an opponent and, rather than die due to the bond, simply become a pure Ghost-type. Considering that Trevenant also only becomes a tree when it dies, this forest guardian could use this move with deadly force and not suffer much for it.
3. Giratina Is The Ghost-Type Pokémon God Of All Bad Things
Giratina is a Legendary Pokémon and a Ghost/Dragon-type. It was introduced in Gen 4 and, due to its extreme violence, was banished to the Distortion World by Arceus, the Legendary Pokémon who created the universe. Giratina is considered the god of death and afterlife, and of all things that cause death (war, plague, famine, and so on). Its moves are Shadow Sneak, Destiny Bond, and Shadow Force. Its ability is Pressure.
Giratina ranks #3 because its behavior is alarming, and it is powerful, but it's moves are also quite scary. Destiny Bond was already covered (and Giratina probably can't die), but Shadow Force and Shadow Sneak are terrifying when used by this Pokémon. Shadow Sneak extends the user's shadow and attacks the opponent from behind; Shadow Force makes the user invulnerable and the attack itself causes damage through Protect. This Pokémon is end-of-the-world scary, but since it's trapped it gets relegated to third place rather than first.
2. Spiritomb Are Destructive, Mischievous Ghost-Type Pokémon Spirits
Spiritomb is a Ghost/Dark-type Pokémon, and is the amalgamation of 108 spirits. It is both mischievous and destructive, and was bound to a keystone as punishment for misdeeds. Its moves are Curse, Confuse Ray, and Shadow Sneak, and its abilities are Pressure and Infiltrator.
Spiritomb ranks second for all four factors: appearance, behavior, move-set and abilities. Pressure doesn't actually do more than cause opponents to use double the PP of each move they use, but in an actual encounter this ability would cause a sense of dread. On top of that, Confuse Ray and Shadow Sneak, as previously mentioned, are terrifying moves on their own, and Infiltrator allows the user to ignore an opponent's defensive moves. If used by this vicious Pokémon, victims will certainly be in for a fright.
1. Gengar Is The Original Ghost-Type Pokémon Terror
The one and only Ghost/Poison-type, giant-tongued Pokémon Gengar steals the life of its victim. It likes to hide in shadows and mimic victims to make them paranoid and frightened, and it enjoys their fear. The Pokémon Shield description of Gigantamax Gengar is that "if you stand in front of its mouth, you'll hear your loved ones' voices calling to you." Gengar knows the moves Hypnosis (which is not a Ghost-type move, but it puts opponents to sleep), Nightmare, Destiny Bond, Curse, and Confuse Ray. Its abilities are Cursed Body (can disable a move used against Gengar for 4 turns), and Levitate (immunity against Ground attacks).
Gengar ranks #1 as the most horrifying Ghost-type Pokémon for all four categories. Its behavior is especially unnerving, and the fact that this Pokémon can put opponents to sleep, curse them, confuse them to the point of self-harm, and afflict them with nightmares should send every trainer running in the opposite direction.
Ghost-type Pokémon, despite their destructive and sometimes murderous habits, are still popular additions to trainers' teams. And these, the five scariest Ghost-type Pokémon as of Gen 8, would make excellent teammates - as long as they don't terrorize their trainers.