Tiger by the tail

Can anyone give me the origin and meaning(s) of the expression "having a tiger by the tail"?

I can give you the meaning but none of my references gave an origin. I took a guess:

HAVE A TIGER BY THE TAIL - "Cope with an obsession; pursue an idea, a talent or even a vice obsessively; face a trying problem." From The Dictionary of Cliches by James Rogers (Ballantine Books, New York, 1985).

There's a similar proverb: "He who rides a tiger is afraid to dismount - Once a dangerous or troublesome venture is begun, the safest course is to carry it through to the end. 1875 W. Scarborough 'Collection of Chinese Proverbs.'" But I am guess "tiger by the tail" might have to do with "The Story of Little Black Sambo" by Helen Bannerman:
".And the Tigers were very, very
angry, but still they would not let go of each other's tails.
And they were so angry, that they ran round the tree,
trying to eat each other up, and they ran faster
and faster, till they were whirling round so fast
that you couldn't see their legs at all.

And they still ran faster and faster and faster, till
they all just melted away, and there was nothing
left but a great big pool of melted butter (or
'ghi,' as it is called in India) round
the foot of the tree."
www.ishipress.com/ sambo.htm Accessed May 12, 2003.

Once you let go of the tiger's tail, it is going to eat you!

I think the phrase means that you've taken up a position which you thought would give you control but in fact is going to be very difficult or dangerous to escape from.