From YouTube:

[8] FATTENING FROGS FOR SNAKES
As recorded by Sonny Boy Williamson [II], 1957.

It took me a long time to find out my mistake, (2x)
But I betcha my bottom dollar, I'm not fattenin' no more frogs for snakes.

I found out my downfall back in nineteen and thirty-eight. (2x)
I'm tellin' all o' my friends, I'm not fattenin' no more frogs for snakes.

In nineteen and fifty-seven I got to correct all o' my mistakes. (2x)
I'm tellin' my friends, my wife and everybody else, I'm not fattenin' no more frogs for snakes.