Wikipedia
Roseben
Roseben (1901–1918) was an American Thoroughbred Hall of Fame race horse who grew to such an enormous size (one inch less than 18 hands) that he was known as "The Big Train." Because of his great size, he was slow to mature but when he finally got moving in his fourth, fifth and sixth years of racing, he was called the greatest sprinter of his time. He ran under weights as high as 130 pounds in 59 of his races, and as high as 140 pounds in 29 races. On more than one occasion, he won under 144 pounds, 146 pounds, and 147 pounds. Once he carried 150 pounds and finished second. He conceded huge weights to his opponents in 86 of his starts, once giving away 60 pounds at Brighton Beach Race Course in 1907 and still winning by two lengths.