SRS the version I knew went:

THREE CRAWS
Three craws, sat upon a wa',
Sat upon a wa',
Sat upon a wa-ah-ah-ah,
Three craws, sat upon a wa',
On a cold and a frosty morning.

First craw fell and broke his jaw
etc

Second craw went to tell his maw
etc

Third craw wasnae there at a'
etc