The Lord of the Mountain
The Lord of the Mountain is a unique mountable creature that you can find at the top of Satori Mountain (south of Ridgeland Tower).
You will know if the rare creature is in the area if there is a large blue glow at the top of the mountain.
You can mount is through normal means, however, it may take time to soothe it as you need at least two full circles of stamina in order to subdue it.
The horse has maxed-out attributes, which makes it faster compared to any other creatures in the game. However, the creature cannot be registered at stables, but it can be registered in your compendium, so make sure that you take a picture of it before you let it free.
So I recently was riding the lord of the mountain in game for quite some time. I hopped off for a split second to grab an item and found that the sky turned red in the middle of the day. I realized it was the blood moon and quickly jumped back on the mount in fear he would vanish. As soon as I mounted however the blood moon stopped. I messed around a few different times and found that time would continue passing and a blood moon would never rise as long as the lord of the mountain was mounted but if at any time you got off the lord, no matter what time of day, you would have about 3 seconds until the blood moon activated and the lord of the mountain was sent away. I just thought this was a cool addition since you can basically stop the blood moon. Also a small side note I found interesting, just like a regular horse you can feed the lord of the mountain apples.
They have the same faces as one of the twilight princess light spirits. I think its faron. The lord of the mountain has a similar appearance as well, so Id say the light spirit had something happen to it and it became the blupees and lord of the mountain. Just a crack theory though.
when you find it about 10 blupees will be surrounding it so get a few bomb arrows and shoot in the center to get alot of rupees. this is one of my farming methods I thought of but I have not tested it yet because bomb arrows cost alot and im saving 10000 for my fourth fairy fountain. just make sure to walk away or teleport away then come back and the blupees should be back.