I have heard Eskimo Nell attributed to both A P Herbert & Noel Coward. I think Coward quite likely, actually: remember "Even cariboux lie about and snooze" in 'Mad Dogs & Englishmen'; & cf Deadwood Dick having to be content with "A moose or two, a caribou, A bison cow or a crow; But Deadwood Dick was King of the Prick, And he found it fucking slow". Coward perhaps had a penchant for 'caribou' as a rhyme-word.