I've checked the mysterious pond again and the mystical blue horse creature does respawn there every now and then. A few seconds after I got off, the Lord of the Mountain bounded quickly away and disappeared in a puff of blue smoke. Eventually, in the morning, I noticed some other random curiosity and I dismounted temporarily to check it out. It was clearly an exceptional speciman, and I was ecstatic at my discovery. After a brief amount of testing, I realized that this 'horse' not only had a full 5 stamina, but also seemed to have higher base move speed than any other horse I'd found thus far. Luckily I had a bunch of stamina replenishing food, so I was eventually able to tame it like I would any other horse. The Lord of the Mountain is a one of the creatures found in The Legend of Zelda: Breath of the Wild. Surprisingly, I could, and it immediately tried to buck me off. It looked vaguely horse-like, so I snuck up behind it to see if I could mount it. I took a picture and the Sheikah Slate informed me that this creature was called the Lord of the Mountain.
A herd of Blupees surrounded a shallow pond, and standing regally in the center of the pond was a blue horse-like creature with four eyes and golden wreaths for antlers. Curious, I climbed up and was met with a stunning sight. One day, as I traveled the plains of Hyrule at night, I saw a blue light emanating from Satori Mountain.