Octopid

Octopids are a legendary species of aquatic humanoid lifeform prevalent in The Little Mermaid franchise, largely as enemies. They resembled a combination between cephalopod mullusks (such as octopi, squids, or cuttlefish) and humans. Notable members of the species included the sea witches Ursula and Morgana.

Biology and Society
Specific details on the Octopid race are unknown, although their constantly coming into conflict with the Merpeople in the franchise in general hints that the Octopids and the Merpeople maintain a severe feud against each other. Unlike Merpeople, Octopids, or at the very least Ursula, have no qualms regarding eating live seafood. This is especially evident by her eating a shrimp live. Generally, they were green in skin-color, although some members, such as Ursula, gained a different color such as Purple.

Owing to their cepholopod-like nature, Octopids were able to use their tentacles as both arms and legs. However, unlike true cepholopods, they do possess a skeletal system. This is especially evident in Ursula's death when she was electrocuted at such a frequency that her skeleton shined through, and when Morgana received an electrical shock when an initial attempt to steal the Trident from the seal failed.

Abilities
Octopids possess a great deal of magical abilities and potion making, evidenced by Ursula. They could practice magic either via specialized potions, by harnessing talismans, or by other methods. However, the soul script magic used by Ursula apparently was not commonly practiced, as Ursula was the only known member of the species to do so.

Besides their magical abilities, they also were able to shapeshift and spew ink, similar to other cephalopods.

Appearances
The race itself first appeared in The Little Mermaid with the main antagonist, Ursula.

The race was expanded on in the TV series, specifically in the episode "Heroes", where Ursula revived a deceased Octopid army that she had formerly commanded. It also hinted that the reason for Ursula's exile was because she made dark tridents and tried to attack Atlantica. On a related note, this was also the first and only entry in the franchise that gave the race its name.

The race appeared again in the form of Morgana, the sister of the then-long deceased Ursula, as well as their mother.

Trivia

 * Octopids don't exist by name in the real world, but they are based on another legendary creature, the Cecalia, which was half-octopus, half-woman.