I sang "Once On A Cannibal Isle" to my two sons; it was sung to me when tiny as a lullaby by my late father [b 1925], whose mother [b 1897] sang it to HIM, whose mother had sing it to HER.
I'd never seen any reference to it anywhere and then, out of theblue, MANY years ago, saw it in print in an EFDSS magazine- possibly in the 1980s. I think it was dow as a music hall song.
It certainly made an impression on several generations of babies in my family!