That dog will hunt
This is Old Southern slang for finding something agreeable. Dogs can be found to be more utilitarian pet than cats, especially when it comes to assisting the master in hunting. Hunting dogs would be used to sniff out game or to retrieve fowl after they have been shot from midair. Only certain dogs would be of use to its master during a hunt.
usage:
Jim: What do you say we run down to Bob Evans for breakfast?
Duke: That dog will hunt!
It can also be used to show negativity or disagreement with an idea. (That dog won't hunt!)