This is not legal in most places but theres talks of other animals fighting so why not ask.
I know it is popular with Bitcoin and gamblings.
I would not even be interested in this whatsoever
And OP why do you think this would be popular with bitcoin?? Please tell me not because it's an illegal sport or whatever it's called!
If you ask me such illegalities are likely to be run with fiat not bitcoin which might be inconvenient with its long conformation times.