Goliath is the world's tallest horse. At 6'5", the Percheron draft horse is twice the size of average equines. The 2,500 pound horse is owned by Priefert Ranch Equipment of Mount Pleasant, Texas. From the Missoulian:
Goliath is so tall it's hard for him to graze – his neck just isn't long enough to get his mouth to grass. The horse has to stretch his front legs apart, like a foal, in order to reach the ground.
He goes through 18 pounds of Pilgrim's Pride Grain, 40 pounds of Coastal Bermuda hay and 20 gallons of water a day…
Goliath makes 100 to 150 promotional appearances and travels 40,000 miles in his custom-built horse trailer every year.
UPDATE: Goliath may hold the Guinness World Record of tallest horse, but a Lincolnshire, UK shire gelding named Cracker may be an inch more worthy of the title. Link (Thanks, Richard Leedham-Green!)