kincsem (racehorse)
Hungarian: "My treasure", "My darling"
Real-life Hungarian racehorse from the late 19th century, she has by far the longest undefeated race record of any racehorse, being undefeated in all of her 54 races (second best record is 25 races by Black Caviar).
She was a chestnut (or liver chestnut) mare with no markings, often described as ugly and noted to have a quirky personality. She was also something of a living legend figure, thus much of her life story should be taken with a grain of salt.
Although she had few foals, her mare-line survives in modern times through both of her surviving fillies. One of the most notable modern day descendant of hers is Camelot, who challenged the British Triple Crown.