Skate Mother
FluxuskrÃmsl, Skötumóðir, Vatnsandi; CR4
Alignment: NG
Home plane: likely Elemental Plane of Water
Rays do not enjoy a good reputation. Ixitxachitls are the main reasons for this, but stingrays and electric rays are feared by mortals too. But there’s one being who is especially horrible to sailors and fishermen—the dreaded skate mother. This huge beast grabs and sinks boats with its fins, and then disembowels unlucky passengers with its nine stingers.
Of course, wise bloods of the Bottomless Deep know better. Skate mothers aren’t bloodthirsty monsters—they are protectors of their kin. These creatures herd stingrays and skates around themselves, leading their shoals through the Silt Flats and the Bay of Life. No one really knows the dark of skate mothers—some reckon they are warden beasts beholden to the animal lord of rays, others trace their lineage from ixitxachitls who betrayed Demogorgon and turned to goodness.
COMBAT: Skate mothers are easily recognisable by two features—claws on their fins and nine barbed tails. When attacked, they generally try to swim away, using their innate powers of invisibility to escape. But when they or their shoal can’t avoid danger, the skate mother recklessly attacks. It tries to grab an enemy with its clawed fins, and then bites and stings it. If the skate itself is grappled, it can unleash an electric shock to get free. This shock is an extension of the electric sense that allows rays to sense nearby creatures, much like sharks can.
HABITAT/SOCIETY: Skate mothers can communicate with rays and travel together with shoals of manta rays and other such fishes. Different skate mothers tend to herd several different species at once, like stingrays or sawfish. They protect their brood from danger, and lead them to the most bountiful feeding grounds. Good-aligned cutters try to avoid harming skate mothers and their shoals. In turn, skate mothers often work alongside marine druids and armies of the Elemental Good. Eating skate mothers is dangerous, for their flesh is poisonous. However, while inedible, the bodies of skate mothers are nonetheless valuable for their stone-like organ that can be used to cast invisibility spells.
ECOLOGY: Like other rays, skate mothers feed on small invertebrates they pick off from the reefs and earthbergs of the plane. They mate approximately once every two years and birth live offspring in batches of up to five.
Source: Margarita. Mythwatch: Skate Mother is homebrew, based upon the creature from Icelandic folklore. Credit to https://abookofcreatures.com/ for informing me of this monster.