Creatures are non-sapient organisms, of which all known specimens are native to Spherus Magna. They each have some form of organic composition, varying from being partially biomechanical to the entirety. Creatures that inhabit the Matoran Universe are falsely regarded as Rahi, despite their foreign origin. Those Creatures that do have a bone structure possess a metallic one.
The creatures of Spherus Magna vary in terms of biomechanical composition. Some are entirely organic, while the bodies of others, like Rock Steeds, have various biomechanical elements. They reproduce biologically, and although there may be some variety in the way this is achieved, it is known that Sea Squids, at least, lay eggs.
- Ancient Sea Behemoth - A giant marine creature awakened by Toa Mahri Kongu using his Kanohi Zatth.
- Bird (unnamed) - Multiple species of organic birds.
- Blood Snail - An organic marine snail, which can give one bad breath when eaten.
- Clam (unnamed) - An organic clam found on the shores of the island of Mata Nui.
- Coral - An organism which forms reefs, including some in the Black Water.
- Dragonfly (unnamed) - An organic dragonfly which made a home on the island of Mata Nui.
- Fish (unnamed) - Multiple species of organic fish.
- Giant Shark - An organic shark, of which one dead specimen was revived by Toa Mahri Matoro using his Kanohi Tryna to battle against Barraki Pridak and Ehlek.
- Giant Squid - An organic gigantic squid used in the army of Barraki Kalmah.
- Lightfish - An organic, bioluminescent jellyfish used for illumination.
- Razorcrab - A crab-like creature used as a defense for Mahri Nui.
- Seahorse (unnamed) - An organic seahorse.
- Sea Squid - An organic, vampiric squid bred by Barraki Kalmah and used in the armies of the Barraki.
- Snail (unnamed) - An organic conical snail found on the shores of the island of Mata Nui.
- Starfish (unnamed) - An organic orange starfish found on the shores of the island of Mata Nui.
- Underwater Insects - Various species of organic marine insect used in the army of Barraki Takadox.
- Underwater Rays - Organic marine rays used in Barraki Mantax's army.
- Venom Eel - An organic poisonous eel used in the army of Barraki Ehlek.
- Aquatic Beast (Unnamed) - A dinosaur-like creature that the inhabitants used to travel across Aqua Magna.
- Cave Shrike - A desert-dwelling bird creature
- Desert Leech - Creatures that nest on the roofs of caves, dropping down on any intruders and sucking out their life energy
- Dune Snake - A serpentine desert creature known to live in nests and possessing fangs with a powerful venom
- Dune Spider - A creature that uses spikes as a natural defense
- Dune Wolf - A lupine creature
- Giant Scorpion - A species of cave-dwelling arachnid
- Gravel Hawk - A species of bird found on mountain peaks that are considered a delicacy by the Glatorian and Agori
- Iron Wolf - A biomechanical creature created from an existing creature by the Great Beings, known to hunt in packs
- Mountain Worm - A worm creature encountered near Iconox
- Rat (unnamed) - Ordinary rodents
- Rock Jackal - A jackal creature
- Rock Steed - A large, dangerous species used by Bone Hunters as mounts
- Sandray - A desert animal that lives in the unstable terrain of the Sea of Liquid Sand
- Sand Bat - A winged, python-like creature known for attacking from beneath the sand
- Sand Dragon - A desert creature known to shed their skin
- Sand Flea - A desert insect whose colonies have been known to be scattered by sandstorms
- Sand Fox - A small canine creature that inhabits the deserts
- Sand Mite - A microscopic desert creature; used as an insult by Glatorian towards Agori
- Sand Stalker - A quadrupedal creature bred for endurance and used by Agori and Glatorian as mounts
- Sand Worm - A desert creature
- Scarabax Beetle - A species of desert insect
- Click - A Scarabax Beetle who partnered with Mata Nui
- Skopio - A large desert creature upon which Telluris based his Skopio XV-1 vehicle
- Spiked Worm - A worm creature whose larvae burrows into other organisms before killing them
- Spider Beetle - An insect creature
- Spikit - A vicious two-headed creature used by the Agori to pull wagons and carts
- Striker - A bird with a five-foot wingspan that has claws that can penetrate armor
- Sun-Rock Dragon - A dragon creature
- Sun Serpent - A serpent creature
- Talon Snake - A snake-like creature with a talon-like growth on the back of its tail; possesses fangs with a venom strong enough to paralyze a Glatorian; also the visual inspiration for the armor and helmet design of Vastus
- Wasteland Wolf - A predatory creature with paws specially adapted to traveling through sand
- Biomechanical dinosaurs - Giant biomechanical reptiles created by the Great Beings
- Giant Lizard (unnamed) - Large organic reptilians