Mammals:
* Manatee: Large, herbivorous marine mammals found in warm coastal waters.
* Marlin: Large, predatory fish known for their long, pointed bills.
* Mantas: Giant rays with wing-like pectoral fins.
* Mola mola: Also known as the ocean sunfish, the heaviest bony fish in the world.
* Monk Seal: A species of seal found in the Mediterranean Sea and the North Atlantic.
Fish:
* Mackerel: A type of fish known for its oily flesh.
* Moray Eel: A long, slender eel with sharp teeth.
* Mudskipper: A type of fish that can survive out of water for extended periods.
* Marlin: Large, powerful fish known for their long bill.
* Mullet: A type of fish that often forms schools.
* Marlin: Large, predatory fish with a long, pointed bill.
Other:
* Mollusks: A diverse group of invertebrates including snails, clams, and squid.
* Mantis Shrimp: A colorful crustacean with powerful claws.
* Mermaid: A mythical creature, often depicted as a woman with a fish tail.
This is not an exhaustive list, but it gives you a good starting point!