The S-1000s are mutants that have only appeared in Blaster Master Zero.
S-1000 resembles a large slug made entirely out of a liquid metal-like substance.
The S-1000s first appear in Area 7; the normally appear if the player passes under a spotlight when in a dungeon. They attack by materializing behind the player and attempt to dash into him. A large amount appear in the enemy rush room, S-1000 Generator; when defeated, they drop a Life Up.
S-1000s that are summoned as a result of walking into a spotlight are immune to all Gun types. However, the ones summoned from the S-1000 Generator are not immune to Blaster or Long Range.
Slug-like enemies that resemble S-1000 appear on Planet Divido. There are fire and ice variants, each living in the desert and glacier areas respectively. The fire ones leave a trail of fire behind them and can shoot fireballs; the ice ones freeze the ground they travel on, and can shoot balls of ice. They do not try to dash into the player, however.