My great-grandfather (dob 1892) would sing a song to me when he was in his late 80s, back in the 1980s. He had dementia at the time, and my grandmother would assure me that if he was in his right mind he wouldn't sing it in front of young girls. I thought it was funny and my sister and I memorized what little he sang to us. I'm sure its incomplete, and I appreciate the versions others have contributed to help fill in the blanks.

Oh, looking through the knot-hole in father's wooden leg,
Who will milk the cow when I'm gone,gone, gone?
Sister get the axe, there's a fly on baby's head
and a boy's best friend is his mother...

he would also sometimes finish this and other songs like, Red Wing "...without a shirt, or any pants."