So apparently this guy has been exposing himself to minute amounts of snake venom over the past 16 years and has developed some impressive resistance to it. Of course there was that one time he flat-lined because of two back-to-back cobra bites. Seems the underlying principle is that the progressive exposure builds IgG antibodies (which makes sense as they would be active in the blood ready to bind to venom immediately when it enters the bloodstream). Don't think I'd have the nuts to give it a go, but makes for a helluva party trick.