I found a Joan Baez recording: https://www.youtube.com/watch?v=TLe82dCbKl4

The Digital Tradition lyrics are a good transcription of the Baez recording:

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DANGER WATERS

And I holler why, and I holler why
And I holler why, the tortoise boy no mon ami

First he give me one, then he give me two
And he give me three and I holler "Lord have mercy"

First we go in a room, make me mama no know
Make me lie on a sofa, make me have-a me labor

Give me back me shillin', give me back me shillin'
You can stand on your own feet now, give me back me shillin'

Hold me tight, hold me tight, danger waters coming baby hold me tight
hold me tight, hold me tight, danger water coming, baby, hold me

@love @courtship @baby @sex @African
recorded by Joan Baez
filename[ DANGWATR
TUNE FILE: DANGWATR
CLICK TO PLAY
SOF

Phil pointed out a recording by the Yoruba Singers. Does the song appear in songbooks or in other recordings?
I didn't find it in Roud or in the Traditional Ballad Index.

The song is on pp 156-157 of my copy of The Joan Baez Songbook, published in 1964 by Ryerson Music Publishers, a division of Vanguard Records. Here are the notes:

This song is typical of the exciting "Highlife" music heard in the cafes of Ghana. It shows the influence of American jazz and Latin American rhythms on West African native musics, indicating a direction in musical diffusion which ethnomusicologists are first beginning to notice after years of studying in the reverse direction, from Africa to America. Its poetry, too, is worthy of notice for it exhibits a fluidity of words and metaphors based on ordinary speech patterns which strike home directly, if sometimes savagely. (also quoted above by WyoWoman, who was last seen in Seattle).

Notice that in the link Phil gave, the boy is a "Yoruba boy," not a "tortoise boy." the Yoruba people are in Nigeria and Benin.
-Joe-