A.D. Carrol is a waitress in Houston, Texas who on February 13, 2008 received a thoroughbred horse as a tip. Her benefactor requested to remain anonymous, but is a regular at the restaurant Carrol works at. The man is reported to have 50 thoroughbred horses at a stable 40 miles out of Houston. The horse is five years old and named Mailman Express. Carrol has described the horse as being docile and reserved.

• Topix.net: A.D. Carrol
• Google News: A.D. Carrol
• The New York Times: Thank You for the Coffee, Ma'am. Your Tip Is at the Stable. (February 27, 2008)
  • "And not just any horse: a thoroughbred race horse named Mailman Express who had won $15,000 at the track and was too "sored up," in the words of his keeper, Curley Linehan, to race any more."
• FOXNews.com: Texas Waitress Gets Horse as a Tip (February 27, 2008)
• ABC News: Is a Horse a Horse? Not When It's a Tip (February 27, 2008)
  • "When she lived in California in 1963, she was in a car accident that killed her 6-year-old son. Her husband died of a heart attack in 1983, and a second husband was murdered."
• Chron.com: Galloping gratuity: Waitress gets horse as a tip (February 27, 2008)