Decided to update the "Sharky Boy" design a bit, since I've been wanting to make use of it for something in my universe since I like the design...

I ended up deciding to make use of them as an amphibious, shark-like alien race! Their homeworld currently doesn't have a name, nor does their race, and I haven't decided what (if any) affiliations they'll have with other space-faring groups and races, but I have given them and their world a bit of thought...

The shark-folk come from a very wet, oceanic world that is over 80% covered in seas, with most of these seas being a few hundred feet deep at most, but with some deeper ocean areas. Much of the planet is warm and humid, most of it covered in thin fog and haze consistently, with lots of rain as well. The landmasses are mostly small islands, sandbars, mangroves, reefs, and things of that nature. The shark-folk are amphibious, and able to survive on land due to the moisture present in the atmosphere, and since there's far less predators and parasites above the water, they build homes on the sandbars, in the mangroves, on the islands, and even on stilts above the seas, but much of their daily lives still occur in or very near the water.

They feature gill-like slits to the pectoral region, and these gills can work in any sufficiently moist environment, which enables them to live on land thanks to the high humidity and moisture of their environment, the haze and fog and rains and sea spray from the waves keeping the air moist enough for them to breathe comfortably. Any potential "dry-suit" or spacesuit would incorporate small water tanks to keep the gills hydrated.

They communicate both through a language consisting of mainly clicks and squeaks similar to dolphins, and through a sort of telepathy-like electromagnetic wave language, transmitted and received by organs in their brains. The electromagnetic language has the advantage of being silent and is an evolutionary advantage as it enables the shark-folk to communicate hunting strategies without alerting their prey beyond any vague feelings or sensations the electromagnetic waves may cause in nearby creatures. This ability has a bit of a shorter range on land, but is still useful in the open air for silently conveying information.

When interacting with other races, Zerdans will be able to partially communicate with the sharks via their "telepathic" means due to having similar organs used for their empathic bonds, but the process of telepathic communication will give both races a headache after a while due to the frequencies used being a bit different. Keahi are vaguely aware of the magnetic communication (much like how they are naturally somewhat receptive to Zerdan empathic waves) but can't decipher it in any meaningful way, and it just makes them vaguely uneasy.

A small group of these sharks somehow found their way to Keone and live in the oceans there, generally not coming into contact with the native Keahi and the Keahi regard the shark-folk as cryptids, only really confirming their presence once the Dominion used advanced technology to properly survey the planet completely. Other small populations might exist on worlds like Demeter as well.