'Blood on Satan's Claw' (1971) – Piers Haggard.

Back in the day when folk used to meet in boozers and communicate freely without the aid of pocket-phones, I made the brief acquaintance of a singularly odd fellow who made an ostentatious claim to being some manner of 'suburban magi', and he most certainly looked the part, having a riotous shock of ice-white hair, outsized tombstone teeth, and a grim, unwaveringly flinty stare that could straighten horseshoes! Anyhoo! I digress, said squirrelly gent had quite a thing about films that contained an 'authenticity of evil', again, I merely put this fanciful notion down to his habitual usage of magic mushrooms, and the consistently high levels of ethanol in his bloodstream, and within his aggressive litany of boozy badinage, he frequently, and somewhat oppressively suggested that I watch the searingly malevolent 'Blood on Satan's Claw', and a few years later, when I finally got round to seeing it on the late night tele, I couldn't help but recall what this manifestly strange individual had said about its alleged 'authenticity of evil'....