Matango - Attack of the Mushroom People (1963)

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One of my all time favorite classic horror movies! Its a must see! MATANGO scores very high on the slow-burn creepiness meter, and the story of a bunch of hapless castaways slowly descending in to distrust and madness is utterly compelling. What they find on the island is truly disturbing, and I can't put into words how thankful I am for not having seen this during my formative years. This is one of those movies that can royally mess up your mind if you're a little kid.