This is Chase172.
ATU0275 race of the fox and the crayfish
K0011.2 race won by deception: riding on the tack
Clarke has 5 and Klipple has 4, and Flowers has 6, including crab hanging on fox which she lists as ATU0250 Swimming Match of the fish
Baer notes: "There is no way of knowing when Harris first collected this tale; its first appearance as an Uncle Remus tale was in Uncle Remus's Magazine, 1908. However we know that he kept outlines of tales sometimes for years hoping to hear an oral version."
conclusion: "This one is as likely to have been brought to this country by slaves from Africa as to have been acquired later from the European tradition."