Here's the version from One Hundred English Folksongs, edited by Cecil Sharp (1916). It's almost the same as the Nancy Thym version I posted above, but it has fewer verses and the beginning makes more sense.
-Joe Offer-

THE TWO MAGICIANS

She looked out of the window
As white as any milk
He looked into the window
As black as any silk

Refrain
"Hulloa, hulloa, hulloa, hulloa
You coal black smith
You have done me no harm
You never shall change my maiden name
That I have kept so long
I'd rather die a maid,"
Yes, but then she said,
"And be buried all in my grave,
Than I'd have such a nasty,
Husky, dusky, musty, fusky
Coal black smith!
A maiden I will die!"

Then she became a duck,
A duck all on the stream
And he became a water-dog
And fetched her back again
Refrain

Then she became a hare,
A hare upon the plain,
And he became a greyhound dog
And fetched her back again.
Refrain

Then she became a fly
A fly all in the air
And he became a spider
And fetched her to his lair
Refrain^^^