Spaceshifting Wormhole
From SmashWiki, the Super Smash Bros. wiki
A Spaceshifting Wormhole is a gameplay mechanic in the Subspace Emissary. Spaceshifting Wormholes appear as dark purple portals about the size of Bowser. Their function is to produce an infinite amount of enemies (commonly Mites) up to a set limit; if the player gets rid of one, it simply spawns another. The only way to stop this is to attack and destroy the portal itself. Unlike every other enemy in the game (including Jyks), there is no health bar display for a Spaceshifting Wormhole. Because of this, there's no way to know how much of a beating it can take, or even if it can regenerate health.
