The Untaminble Horse

I was walking around on single player and I came across a house texture ive never seen before. (don't know if it was a normal texture or not because I looked up the textures for horse and never found the texture.) I tried to tame it, so I right-clicked and it would not let me clime on. I also then tried to feed it, but it would not eat or do the idle animation. I was on peaceful, if it matters, and after exiting and saving the world, when I went back on it let me tame it. I was not using any mods or hacks.

I had expected for it to let me tame the horse.

What happened is that it wouldn't even let me get on the horse to tame it.

Steps to Reproduce:
1. create normal world on single player with seed: 5157745125143387008 then go to cords: x=-146, y=64, z=119
2. Find the horse as seen in the pics below
3. try to tame it
4. If you tame it, then maybe it just something that happens every once in a while.