One of the most satisfying horror movies of the ’70s is a collaboration between Spanish Euro-western veterans and American blacklist exiles. A gonzo cast of genre heavyweights — Christopher Lee, Peter Cushing, and Telly Savalas — battle a shape-shifting alien concealed inside the frozen remains of a cave-dwelling creature. The whole thing happens on the Trans-Siberian Express train as it thunders across the frozen tundra. Scary and super cool.