Phazon Harvester Drone

From Wikitroid, the Metroid wiki

Phazon Harvester Drones were created by the Space Pirates exclusively for collecting Phazon. They originated as Goliath-class Heavy Assault Drones and were later converted by the pirates. They are heavily armored; their anti-air weapon system is vulnerable to an overload, but hitting that area with weapons fire would only stun it. Samus' Gunship can destroy it, but only after the planet's shield generator is shut down. Killing the Harvester Drone earns the player a Friend Voucher.

Its appearence vaguely resembles the Metroid Prime.