The San Antonio zoo used to serve rattlesnake meat one day a week. This was some 40 or so years ago; they probably stopped long ago. The rattlesnake is useful in keeping down rodent populations; they are left alone by many cattlemen for that reason.

The 'secret' to good burgers is never use cheap meat sold as hamburger meat.
Another finish to burgers I like is to melt stilton cheese on top.