To tame these guys, you need to go and find a place where you know they spawn, then make a four by four structure two walls high. And then get a argaventise and grab the equus, then put it in the safe structure, nothing SHOULD see you if you stay inside with the equus, but, they usually need rockarrots, but sometimes other things, but I would suggest get some seeds and grow atleast 50 carrots, then when you have your taming food, you can either wait a while for them to get hungry each time, or every minute or two mount them, feed them quickly, then get off, if you do everything correctly you should get your horse! Goodluck! Hope this helped!