In Andrei Tarkovsky's film Stalker, Writer refers to Stalker as Chingachgook four separate times and also Leatherstockings two separate times. I should note that the word Stalker in Russian is defined as a Guide or a Pathfinder. It has nothing to do with the American meaning of Stalker. I had no idea what Chingachgook or Leatherstockings was referring to until I looked it up the first time I Watched Stalker. This Wikipedia article can explain it better than I can: "Chingachgook was a fictional character in four of James Fenimore Cooper's five Leatherstocking Tales, a lone Mohican chief and companion of the series' hero Natty Bumppo. Chingachgook married Wah-ta-Wah who bore him a son Uncas, but she died young. Uncas, at his birth "last of the Mohicans" grew to manhood but was killed in a battle with renegade Magua. Chingachgook dies as an old man in the novel The Pioneers and so is the actual Last of the Mohicans, having outlived his son.
Chingachgook is said to have been modeled after a real-life wandering Mahican basket maker and hunter named Captain John. The fictional character, occasionally called John Mohegan in the series, was an idealized embodiment of the traditional noble savage. The French often refer to Chingachgook as “Le Grand Serpent”, the Great Snake, because he understands the winding ways of men's nature and he can strike a sudden, deadly blow." Leatherstockings refers to the pants Chingachgook wore. So now I know Writer refers to Stalker that way because he is their guide through the Zone and eventually to the room where your innermost desires can come true. If you have faith in yourself!