Bosses are very powerful enemies that often guard or possess a power-up which Samus Aran must kill to obtain the item. This page is a list of bosses in the entire Metroid series.
Metroid
Kraid and Ridley can be killed in either order, but must both be defeated to access Mother Brain's lair.
- Kraid - One of two bosses necessary to defeat in order to access region of final boss
- Ridley - One of two bosses necessary to defeat in order to access region of final boss
- Mother Brain - Final boss
Metroid: Zero Mission
- King Worm - Carrier of the Charge Beam upgrade
- Mua - Grants access to the rest of the area in which it presides
- Kraid - Carrier of the Speed Boost upgrade
- Kiru Giru - Grants access to Ridley's Lair
- Imago - Carrier of the Super Missile upgrade
- Ridley - Carrier of an Unknown Item, later discovered to be the Gravity Suit
- Mother Brain - "Final" boss before Samus is shot down during her retreat from Zebes
- Ruins Test - Returns not only a Power Suit to Samus, but also grants access to the three previously Unknown Items: the Gravity Suit upgrade, the Space Jump and the Plasma Beam.
- Ridley Robot - True final boss
Removed: Crocomire
Metroid Prime
In the Wii versions of Prime, each boss rewards Samus with an Orange Credit. Any bosses that do not do this are marked with an asterisk.
- Parasite Queen
- Hive Mecha
- Plated Beetle
- Incinerator Drone
- Flaahgra
- Sheegoth
- Thardus
- Elite Pirates*
- Cloaked Drone*
- Phazon Elite*
- Omega Pirate
- Meta Ridley
- Metroid Prime (2)
Metroid Prime Hunters: First Hunt
- A green Samus Aran (Holographic projection)
Metroid Prime Hunters
- Kanden
- Guardian
- Spire
- Weavel
- Sylux
- Noxus
- Trace
- Cretaphid v1
- Cretaphid v2
- Cretaphid v3
- Cretaphid v4
- Slench v1
- Slench v2
- Slench v3
- Slench v4
- Fire Spawn
- Arctic Spawn
- Gorea (2)
Metroid Prime 2: Echoes
Except for the Dark Missile Trooper and Caretaker Class Drone, the Wii versions of Echoes reward Purple Credits for each boss killed.
- Alpha Splinter/Dark Alpha Splinter
- Alpha Sandigger/Bomb Guardian
- Jump Guardian
- Amorbis
- Dark Missile Trooper
- Boost Guardian
- Alpha Blogg
- Grapple Guardian
- Chykka
- Spider Guardian
- Power Bomb Guardian
- Caretaker Class Drone
- Quadraxis
- Emperor Ing
- Dark Samus (3)
Removed: Mad AI
Metroid Prime 3: Corruption
Scan images from the Boss Creatures section of the Logbook.
All bosses except for the second Berserker Lord and the Mining cannon reward Gold Credits.
- Berserker Lord (2)
- Meta Ridley
- Rundas
- Korakk Beast
- Mogenar
- Steamlord (3)
- Defense Drone
- Ghor
- Helios
- Gandrayda
- Mining cannon
- Commander Squad
- Omega Ridley
- Metroid Hatcher (3)
- Dark Samus
- Aurora Unit 313 (2)
Removed: Crocomire
Metroid Prime: Federation Force
Metroid II: Return of Samus
Super Metroid
Super Metroid incorporates sub-bosses, known as Minibosses. A Miniboss is a minor boss. For example, Crocomire is the miniboss of Norfair, as, while he is fought as a boss, he does not unlock one of the statues above Tourian. Minibosses are marked with an asterisk (*):
- Ridley (Ceres Space Colony)
- Torizo*
- Spore Spawn*
- Kraid
- Crocomire*
- Phantoon
- Botwoon*
- Draygon
- Gold Torizo*
- Ridley (full length battle)
- Mother Brain (2)
Metroid: Other M
- Brug Mass
- Fune and Namihe
- Groganch
- King Kihunter
- Mystery Creature
- Goyagma
- RB176 Ferrocrusher
- Rhedogian
- Vorash
- Ridley
- Nightmare
- Queen Metroid
- MB
- Phantoon
Metroid Fusion
Again, asterisks (*) indicate minibosses.
- Arachnus
- Elephant Bird*
- Zazabi
- Serris
- B.O.X. Security Robot*
- Mega Core-X
- Scientist*
- Yakuza
- Nettori
- Nightmare
- B.O.X. (second form)*
- Neo-Ridley
- SA-X
- Omega Metroid