Day 1: Siren's Embrace
A group of sea nymphs that entrance others with their song and dance. They pose as a traveling Synchronized swimming group to add more girls to their ranks
The 2 sea creatures are from Season 2 Episode 2: Water World, where the contestants are tasked to create a sea creature hybrid.
Original looks here:
https://www.shadowlordinc.com/tfclip.view?Clip.Id=8163