I have listen a lot of time that Pakistan are cornered tigers in cricket commentary. What does that really mean ?
The original phrase (in English) is "cornered rat", which originated in the 1800s and became widespread in the early 1900s https://books.google.com/ngrams/graph?content=cornered+rat&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Ccornered%20rat%3B%2Cc0 with the meaning that an animal (or a person) can be much more dangerous when cornered.
Obviously, though, telling your team to fight "like cornered rats" would not have quite the same ring. Tigers sound ever so much more noble and dangerous.
After a bit of reserach, it seems that during the Cricket World Cup 1992, the Captain told his team to play like "cornered tiger" during a speech, and they won the World Cup.
I guess this expression in cricket was then bond with the Pakistan team.
That's it for the story, and for the expression herself, the meaning seems quite clear, a cornered beast (here a tiger, because i guess there's some in Pakistan), as nothing to lose, therefore, he will be even more dangerous.