Doc's version has the sound of a late composition, but I don't know. Is there anything on his album notes that indicates origin?

The song was even done (as Muskrat) by the Everly Brothers, who no doubt learned it from daddy Ike.

The song goes back a lot further than Doc, Don and Phil, though. It is also known as "Woodpecker," and as "Rattlesnake." The earliest versions I know are a couple of 1925 recordings: "Black Snake" by a black singer, John Henry Howard, on Gennett 3124, the other by Uncle Dave Macon as part of his "Muskrat Medley." Here's Howard:

BLACK SNAKE - John Henry Howard

So, black snake, so black snake,
What makes yo' teeth so white?
--next line uncertain-- " Cain't chew tobacco most all of my life ???
Never done nothin' but bite.

Says ol' yellowhammo', yellowhammo' [a bird]
What makes yo' head so red?
Shakin' the baccy most all my life,
And I wonder I hain't been dead.

So muskrat, muskrat,
What makes yo' tail so thick?
Stayed in the mud most all o' my life,
And I wonder I hain't been sick.

Yellowhammo', yellowhammo'
What makes you look so bad?
Lord, shake in the backbone,
And I'm a lonely sad.

My favorite version, which I put together from various traditional sources, is "Woodpecker":

---

WOODPECKER - Trad. arr. Bob Coltman

Woodpecker, woodpecker,
What makes your head so red?
Been peckin' at the wood most all of my life
It's a wonder I ain't dead, I ain't dead, I ain't dead.

Rattlesnake, rattlesnake,
What makes your teeth so white?
Been on the bottom most all of my life,
And I can't do nothin' but bite, nothin' but bite...

Muskrat, muskrat,
Why your back so slick?
Been living in the water most all of my life,
It's a wonder I ain't sick, I ain't sick, I ain't sick.

Groundhog, groundhog,
Why your back so brown?
Been livin' in the ground most all of my life,
It's a wonder I'm still around,, still around, still around.

Rooster, rooster,
Why you crow so hard?
I been scratchin' in the barnyard all of my life,
It's a wonder I ain''t tired, I ain't tired, I ain't tired.

Bobcat, bobcat,
Why your tail so long?
I've been prowlin' these woods most all of my life
It's a wonder I ain't gone, I ain't gone, I ain't gone.

Jaybird, jaybird,
Why do you fly so high?
Been eatin' your corn most all of my life,
It's a wonder I don't die, I don't die, I don't die.

A ~very~ cursory and hasty search through Thomas Talley, Odum and Johnson, Newman I. White, Dorothy Scarborough and other such likely sources has not turned up any earlier printed versions. But given that this song can be titled after any of its animals ("Jaybird" is a possibility), I may have missed it. Fascinating song!

Bob