Pirate Grenadiers are Space Pirates armed with an experimental grenade launcher. The size of the launchers prevent Grenadiers carrying the scythes or beam weapons wielded by other Pirates; the launcher is also ineffective against nearby opponents. At close range, the Grenadiers will resort to ramming. Due to the time it takes to charge the launcher, Samus can easily get out of the grenades' blast radius. Samus first encounters the Grenadiers in the Space Pirate base in Agon after the first battle with Dark Samus. They also appear in the Temple Grounds on the way to Torvus Bog, but they do not respawn on subsequent visits.
- "The Space Pirates have begun to use an experimental energy grenade launcher in the field. The weapon is viewed as a mixed blessing to the Grenadier units: while the grenade launchers are powerful weapons, Grenadiers must leave their rifles behind to carry them. Fast-moving targets can close range on Grenadiers rendering their main weapon somewhat ineffective." — Logbook "Pirate Grenadier" (Metroid Prime 2: Echoes)