Not only scarce but dangerous . Merfolk (Merbeings) have alway looked down on humans because they pollute the seas and oceans. Very rare is it to see a mermaid on a beach because of this and they will attack if threatened. Merfolk will make their weaponry from shark teeth, fish bones, coral ,and sea urchin quills. Merfolk make very crude armor out of shells and a very strong fabric spun from seaweed and kelp. Merfolk of the tropics have been know to create shields from discarded turtle shells. Merfolk are very different when it comes to gender, unlike males in the animal kingdom mermen are very simple and merwomen are not. Merfolk are more violent than we think, just remember that.
There has been controversy over the differences between water sprites and merbeings, or whether there is really a difference at all, but the following is a list of what I think to be true merbeings:
Feel free to fill in the information.