You might know the name from a 30 metre sculpture in Scotland called the Kelpies of 2 horse heads sticking out of the ground.
Now, the Kelpie in folklore is another shapeshifting creature. They usually look like a horse but may appear like a human. Mostly they would look like a breathtakingly beautiful male human, sometimes with or without hooves. They are said to mostly inhabit the lochs or rivers of Scotland.
The horse is said to have a long wet mane which has waterweeds in them and green seems to be associated with them may they be in horse or human form.
While in Horse form, they would look like a magnificent and tame horse. Tame enough that it looks like you could ride it.
But be warned! You should never ride it. This is because, once you’re on top of the Kelpie, a sort of adhesive would start to form. You would be stuck on top of it and get dragged into the water until you drown. That is when it would devour you.