My kelpie unicorn Lumise

Kelpies are a mythical beasts which lure people and animals in to be drown in their lake for consumption. They have mouths that depending on the size of their prey can open all the way back to the hinge below their eyes. They have long tongues used to pull prey in. They tend to eat their prey either whole or in small chunks if they have to go for long periods without prey venturing to close.
Masters of illusion they can appear as a human or a horse, or in Lumise's case a human and a Unicorn. Then as they lure prey to them all they have to do is have their prey touch them and the prey is now stuck to their body. Only the Kelpie can release them, the only other option for the victim is to cut off the limb attached to the Kelpie, and even then, the Kelpie will bite and kill its prey before they can remove the limb to escape. Their primary drive is for food but older Kelpies will experience a heat or mating cycle in which they will try and impregnate female prey to reproduce.
The baby Kelpie will need three days to hatch from the human host and will burst from their mothers body killing her in the process. Or being a unicorn Kelpie he can quickly form the eggs so that the woman can birth eggs rather than have her torn apart from the birthing process. If Lumise likes breeding with the woman he will make her lay eggs instead of having a live kelpie crawl out of her body. Kelpies have been known to take prey and use them for sexual pleasure as well.