Gulpin

It swallows up opponents to incapacitate them. It can also deal damage to the engulfed enemy. Gulpin (, Gokulin) is a Poison-type Pokémon from the series.

Origin
is a Poison-type Pokémon introduced in, and is categorized within the Pokédex at #316 as the "Stomach Pokémon". It evolves into starting at level 26.

is a move introduced in Generation III which Gulpin can learn in every game. It makes the user recover an amount of HP proportional to the number of times is used before it.

As a Poké Ball Pokémon
Gulpin appears as a Poké Ball summon only in Brawl. When summoned, Gulpin remains stationary, and when an opponent gets close enough, Gulpin opens its mouth wide and swallows them. While trapped by Gulpin, a fighter receives continuous damage, and their opponents can also damage them by hitting Gulpin. The trapped character is abruptly spat out after a few seconds, but can escape earlier by button mashing.

If one of the is swallowed, the player's control will move over to the free one until the trapped one is released.

Glitch
If a character is swallowed by Gulpin while Captain Falcon uses his Final Smash, Blue Falcon, on any not-trapped character, Gulpin disappears and the trapped character enters their T-pose during the duration of the Final Smash.