It would be hard to imagine anything less graceful than a 1 legged fish. It is a humorous way of saying I am very ungraceful.

Hi Scarlett, A fish is supposed to balance and propel itself gracefully using its fins. It would be odd to imagine a fish which has only one leg. One would imagine it to be ungainly both in water and on land (if it were ever possible). Therefore, I would feel that the use of "graceful" and "one-legged" is a playful contrast and refers to a clumsy person. Cheers, Lance

means nothing