Gimcrack was a small gray Thoroughbred, standing at 14.2 hands (58 inches, 147 cm) and sired by Cripple, a son of the Godolphin Arabian; his dam, Miss Elliot, was by (Grisewood's) Partner.

Lady Sarah Lennox wrote of Gimcrack in a letter dated to 12 July 1765: "There was a meeting of two days at Newmarket this time of year, to see the sweetest little horse run that ever was; his name is Gimcrack, he is delightful.

Lord Rockingham, the Duke of Grafton, and General Conway kissed hands the day Gimcrack ran.

Despite his small stature, Gimcrack was widely successful, winning 27 of his 36 races in a turf career spanning 7 seasons.

A brick and stone pillar marks his grave to the west of the old walled garden.