Mook, now for aquatic environments. Either they will be equipped with scuba gear (masks and air tanks), become more fish-like, etc. You'll definitely encounter them Down the Drain or even Bubblegloop Swamp. This most commonly occurs with the Mascot Mook. If it is an underwater level, then the hero is also given swimming skills so they can face these mooks as if they were in land; the difficulty in this case is that the jumping on head option is usually taken away, making it impossible to avoid Collision Damage (and forcing you to just avoid these guys) unless some other weapon is given. The other option (when on land) is that these guys jump in and out of water where they are unapproachable because of the hero's Super Drowning Skills, so you have to hit them while they are out of it (if they can be damaged, that is). Some games (like Mario) may have the same enemy show up in both roles, others will have different ones for the two environments. Compare Gas Mask Mooks; a Sub-Trope of Faceless Goons.
Examples:Anime and Manga
- The various Gundam shows typically have at least one type of mass-produced underwater mobile suits for the main Gundam to fight.
- The original Mobile Suit Gundam and it's spinoffs' Gog, Acguy and Z'Gok.
- Zeta Gundam's Zaku Marine, which was actually an unused design from the original series that never made it into the show, brought out of retirement for a decoy operation.
- ZZ Gundam's Capule, which later appears in Turn A Gundam on the Earth forces side as the Kapool.
- G Gundam's Pescatore, a Mexican submersible MS which inexplicably has a face like a parrot.
- Gundam Wing's appropriately named (for once) Cancer and Pisces.
- Gundam SEED's Goon and Snow.
- The arcade version of Contra has two of these that jump out of the water at the beginning of the game, and nowhere else.
- There is this kind of Genesis Clone in Crisis Core, namely the ones which Zack beats with a parasol.
- Deus Ex has a few Diver enemies on the way back from the underwater lab.
- The Ecco The Dolphin series is packed with hordes of these, given that a lot of it takes place under the ocean.
- Final Fantasys I, III, V, VI, VII, and X have underwater dungeons, and thus, enemies appropriate to the area (sea urchins, pirahnas, octopuses, etc.)
- GoldenEye (1997) and The World Is Not Enough's video game adaptations.
- Jazz Jackrabbit 2 has turtles on lifebuoys. Though they only appear in one level and there's about three of them.
- There's an underwater version of the Mettaur, which has scuba gear and stuff.
- In Metroid: Fusion, the X seem to be able to combine the forms of Space Pirates and some species of carnivorous fish to make Mer-Pirates.
- Mini Robot Wars has the land-based stealth unit called the Mole. In the New Game+, it gets the ability to swim on the water surface!
"Ocean doesn't save you from Mole anymore; for it can swim now!"
- And then you get even worse news later- the Giant also gets the ability to travel Amphibiously.
- The standard Pigmask army is supplimented by Navy SQUEALs in the underwater area of Mother 3.
- The underwater level of The Operative: No One Lives Forever features a lot of these.
- Snorkel Zombies, Ducky Tube Zombies, and Dolphin Rider Zombies in Plants vs. Zombies.
- The first boss in Time Crisis 2 is accompanied by aquatic ninjas.
- X-COM: Terror From the Deep replaces the first game's aliens with a variety of aquatic aliens and altered Earth species. Most of them are also able to fight on land.
- Yoshi's Island features a Shy Guy with an inner tube as well as Shy Guys dressed as pirates.
- Justice League Heroes: The Flash has an aquatic Mecha-Mook introduced in the Sunken City level. They start with a water barrier that protects them, and after you destroy it, they will sometimes return to the water to replace it.