I agree that there is no topping the above, but I can think up good explanations all day long.

1. Souvenir of a harpy. They bite.
2. It's a friction burn from seizing Fortune by the forelock.
3. This is from the time I struck while the iron was hot.
4. Oh, I got this plugging a leak in the dormant volcano.
5. Casting my own silver bullets.
6. I don't know where YOU grew up, but around here this is how we stir our coffee.