Merrows, Scrags, Koalinths, Lacedons and other Aquatic versions of a land creature

[Kobold Avenger]

Has anyone bothered to ever use creatures that have mostly been nothing more than footnotes for creatures such as Ogres, Trolls, Hobgoblins and Ghouls in most editions? I generally know nothing about these monsters other than being like X except aquatic. I know they're things we probably have to fill in the blanks on, based on their status as footnotes of various land creatures.

Koalinths especially since they're "Aquatic Hobgoblins" and potentially PC material since normal Hobgoblins have PC stats in 5e, and should have more of a society because they're Hobgoblins.

 

[Paul Farquhar]

They are generally the same as the land version, but with a swim speed and the ability to breathe underwater.

Aquatic umber hulks don't get confuso-vision though, at least not according to my 1st edition Monster Manual.

 

[Arvok]

I have a campaign world in which more than 90% of the surface is ocean. Aquatic races and monsters get used a lot there. I even have a few undead varieties specific to underwater/tidal areas.

 

[Kobold Avenger]

The things is they've really only been footnotes ever. Of course I know their like the land version except with a swim speed.

I don't think anything else has ever been written about any of them.

 

[Satyrn]

I never even considered them, but I have the perfect use for them all, as monsters twisted by the influence of the Great Old One sleeping beneath the waters of my megadungeon . . . I will remedy that right now.

First Thoughts: I'm gonna tack on the telepathy feature that GOO Warlocks get to make them more weird, and work up a list of powers that I'll add on randomly to 1 in 6 of them encountered to make them even weirder. I'm gonna have to go look up various Great Old One info ( like Kobold Press, I believe, has alternate Warlock features for specific GOO patrons that might work) and I have to decide which of these aquatic critters will work. I'll need my books for the next step.

Thanks for the inspiration!