What is "trophonius"

Trophonius (, Trophōnios) was a Greek hero or daimon or god—it was never certain which one—with a rich mythological tradition and an oracular cult at Lebadaea in Boeotia.

Trophonius (foaled 1808) was a British Thoroughbred racehorse and sire and best known for winning the classic 2000 Guineas in 1811. Trophonius won his first three races at Newmarket Racecourse in the spring of 1811, including the Guineas and the Newmarket Stakes on the following afternoon, but ran disappointingly when favourite for the Epsom Derby. He never recovered his best form and was beaten in his remaining seven races. Shortly after his retirement he was sold and exported to stand as a breeding stallion in Russia.