El Topo (1970) IMDb
A black-clad gunslinger takes a naked boy—presumably his son—out into the desert to bury a toy and a picture. They return to a desecrated village and then set out for revenge. Succeeding against the fearsome Colonel, the gunslinger leaves the boy and acquires a girlfriend who propels him onward to fight each of the four great master gunslingers, learning the lessons required for a transcendent rebirth in time to meet the boy again.
A /b/ movie: Surreal allegorical Western built on psychoanalysis, Christianity and Eastern philosophy. Also a classic underground/cult film, the first but not the most famous of the “midnight movies”.
References here: Greaser’s Palace (1972).