Sea spawn

Sea spawn were humanoids that were transformed into hybrid marine creatures by powerful aquatic entities. "They are transformed by the sea and enslaved by powers of the deeps. And the transformation is more than mere fins and tentacles; they come to love their slavery. Poor souls."

- Elminster

Description
Sea spawn were distorted into a ghastly piscine appearance that resembled their original form. Barnacles and coral were encrusted on their cold skin. Their warped bodies were horrific combinations of marine features crossed with humanoid bodies, sometimes alone but at other times simultaneously. Tentacle arms, cephalopod eyes, urchin spines, whale fins, and seaweed hair were but some of the terrifying mutations hosted by unfortunate sea spawn.

Personality
The metamorphosis into a sea spawn changed not only the body but the mind of the victim. Finding joy in enslavement, those turned into sea spawn became fanatically loyal to their creators.

Abilities
Their new aquatically adept forms rendered a sea spawn's gait less effective than before. Whether a mental or physical drawback to the transformation they were also incapable of speech, although they still could understand language. Most notable of their flaws was their inability to stray far from the sea, as they required at least a minute of time submerged underwater to stay alive. To be at all effective in combat sea spawn had to rely on their aberrant anatomical abilities, such as poisonous quills, or tentacles. Otherwise their only means of self defense was to try and pummel their opposition into submission.

Society
Many nefarious masters of the deep could enthrall an unfortunate mortal and transform them into minions. Some did so after making a pact with the mortal, while others merely cursed them. Dragon turtles, krakens, marids, morkoths, sea hags, storm giants, and a host of other seafaring powers held the ability to mark and claim a mortal as a sea spawn.

Ecology
Transformation into a sea spawn did not have to be immediate nor expedient, potentially lasting throughout an individual's life. Their physical transformation also did not necessarily precede their mental changes either, with some being bewitched long before the physical signs were evident.

History
It was said that the human inhabitants of the Purple Rocks were claimed as infants by the kraken Slarkrethel and became fanatics dedicated to him. They grew up as humans but became sea spawn when they reached old age to return to their master. The cult was tended by kraken priests, who were mostly natives but could also include merfolk, merrow, and sea elves.