Siyokoy (Philippine mythology)
The Siyokoy (Syokoy) are creatures in Philippine Mythology which were members of Bantay Tubig (merfolk). They are usually illustrated as green-skinned humanoids that have scaly body coverings, webbed hands and feet, having fins on several parts of their bodies.
...horrifying sea creatures with fish-like bodies and long green tentacles. They drown mortals and eat them. They have gill slits, are colored brown or green, and have scaly skin, comparable to that of fishes.