Murgese stallion, Carletto. A rare blue roan; the only color other than solid black seen in the Murgese breed. Carletto is a young dressage horse. #MurgeseHorses
"Howling Woods" by Kristin Castenschiold.
These aren't the only things out there of course, but it should get you started and keep your drawing busy. Available in smaller, more digestible chunks at www.htdhorses.com :
What a beauty! ♡ ♥ ♡
Визит к единорогу by Andrew Lucas on 500px
Who wouldn't want to wake up to these guys!?!