Have A Tiger By The Tail Meaning

(idiomatic) To be in a difficult or dangerous situation in which one ideally should not remain, but from which one cannot withdraw.

Example: 2009, Jack Dalton, A Country Lawyer, Strategic Book Publishing (2009), ISBN 9781606939413, page 75:
  "Sounds like you have a tiger by the tail. Hawthorne won't go down without a battle and will probably sue you if he wins," Clair admonished.