cowardly lion

noun1

1. •
   (figurative) A person who acts tough but misses a golden opportunity out of fear or cowardice.

   • "This $13 billion mutual fund, which calls itself "classic growth investing, the Janus way," is in reality a cowardly lion." -Forbes
   • "California is right; we trust Washington state will follow in court. Earlier court decisions against the EPA's Cowardly Lion position on global warming suggest legal action may have good prospects." -Seattle Post Intelligencer