Some aquatic variants of BECMI monsters
by Mike HarveyThe Blink Dogfish is a small shark that blinks in to take a bite, and then blinks away. It is annoying and dangerous, but tritons have domesticated them for use as guard and hunting beasts. Blink dogfish are sometimes confused with Phase Piranhas, but the former live in the ocean whereas the latter are native to freshwater rivers in Davania.
Aquatic Kopru are thought to be extinct. They were similar to their amphibian cousins but cold-blooded, able to live in the frigid depths of the sea and even in the Arctic. Aquatic kopru did not have the ability to charm humans, instead they could control fishes, reptiles, and humanoids of piscian or reptilian nature. Aquatic kopru built floating lairs in mid-ocean, neither on the service nor in the depths, but free floating hundreds of feet down. From these lairs they would raid and hunt along with their enslaved servitors; but when they became too big of a nuisance to the devilfish, they were hunted down and exterminated in a wide-ranging war. While there are occasional rumors of sightings even to this day, there have been no reliable reports for a thousand years and most sages believe that they have died out.