What do you think I am?

I have been described as magnificent, powerful, and beautiful. I am centuries old and breathtaking. When I run you see the tension and flexing of muscles rippling through my body. As the wind blows you can see my hair blow, and hear the sounds as I call to the others of my kind. I am a very gregarious creature.
The strong scent of fresh grass always surrounds me. The rumble of my stomach can be heard if you stand real close. My warm wet muzzle will nibble on your hand and tickle you with its short prickly hairs. Occasionally, I may lick you. My tongue is nothing like a cow, rough as sandpaper, mine is smooth and slimy. As you run your hand down my neck you can feel raw strength. My coat is smooth and warm. If you pet in the right direction the hair grows there is no resistance, but I don't like it when you pet the opposite direction. As you pet me I may become more relaxed and prop one of my back legs up.
You can literally see and touch the muscles that make me so magnificent. The prominent "v" between my front legs and large bulges on my forearms are keys to my successful lift off across the pasture. My massive hip and hindquarter muscles allow me to "get up and go!"
On a more sensitive level I have large brown eyes covered by huge eye-lids and long eyelashes. My ears are small, fuzzy and normally point forward. If I am angry they may point backwards. My nostrils will flare as I breathe in and out. I am a loving creature if I am treated properly, and would love nothing than to lie in the sun all day.