Shedinja

Shedinja (Japanese: ヌケニン Nukenin) is a /-type Pokémon introduced in Generation III. It is born from the remains of Nincada when it evolves into Ninjask.

Behavior
Shedinja is an evolutionary byproduct of Nincada's evolution; the discarded husk. This Pokémon is said to have originated from a discarded bug shell, which came to life. Peering into the crack on its back is said to steal one's spirit.

Special abilities
No matter how much a Shedinja is trained, its HP always stays at one as its special ability, Wonder Guard, allows it to take no damage, except from super effective moves.

Trivia

 * Despite having only one HP, Shedinja is able to learn Substitute though it always fails when used due to its HP.
 * Shedinja has the lowest HP of all Pokémon.
 * No other Pokémon has the same type combination as Shedinja.
 * Shedinja is the only Bug-type weak to Dark-type moves.
 * There are two ways to make a Shedinja faint without using super effective moves; one is where the player must send a Pokémon that has the ability Mold Breaker, or another Pokémon that has an ability that ignores all abilities. Also, a Pokémon can use a move like Worry Seed to change Shedinja's ability.
 * Weather like Sandstorm and Hail affects Shedinja, causing it to faint.
 * Shedinja has the lowest base stat total of all fully evolved Pokémon.
 * Shedinja is also the only fully evolved Pokémon who has a lower base stat total than its pre-evolved form.
 * It has the same attack as Ninjask.
 * Status ailments and recoil damage can hit through Wonder Guard, which causes Shedinja to faint.

Etymology
Its name is a portmanteau of the words "shed" and "ninja".