The only living thing I've ever used it on was a snapping turtle who tried to steal my bait when I was fishing.
4 Golden Sabre hollow points into the head and neck, and it was still kicking. They're pretty hard to kill, probably more so than your average feral urban yute...
I Killed a Rattler with my LCP last September. It took all 6 shots - but I only connected with 3!