A Subspace Generator is a gameplay mechanic in the Subspace Emissary. Subspace Generators appear as dark purple portals about the size of Bowser. Their function is to produce enemies until it is destroyed. Each one generates only one type of enemy. There is a set limit on the number of enemies on the screen at any given time, so if the player gets rid of one, it simply spawns another. However, the limit to how many enemies it can spawn is thirty, and if the player can defeat them all, the Generator will simply stop spawning the enemy, but it will not disappear.
Unlike every other enemy in the game (including Jyks), there is no health bar display for a Subspace Generator. Because of this, there is no way to know how much of a beating it can take. This is mainly because they are treated as stage elements, not enemies.