Dar's black tiger is actually a regular striped tiger dyed black. The dye would wash off around the mouth whenever the tiger took a drink, so throughout the film the stripes are often visible around the mouth.
The actor playing the young deposed prince was not allowed to be on the set at the same time as the tiger, so a short stunt person in a wig, photographed from behind, was used in those shots.
Don Coscarelli claims to have read all of Andre Norton's books as a boy. Norton is the author of a novel called "The Beastmaster", in which this movie is loosely based.
Director Don Coscarelli decided to set the story in a sort of Bronze Age milieu because he was a long time fan of Steve Reeves, Ray Harryhausen and sword and sandal flicks.
Although the film fared only modestly at the box office, it steadily built a strong cult following over the years. It subsequently received significant local TV and cable airplay in the USA, notably HBO and TBS where it became a TV mainstay and viewer favorite. Its replay was so common that some dubbed TBS "The Beastmaster Station", and HBO as "Hey, Beastmaster is On".
Don Coscarelli sold off his rights on the story and characters. He has no involvement with the sequels, nor the TV-series, and doesn't see any money from them.
An eighteen years old Demi Moore auditioned several times for the part of Kiri. Although she was Don Coscarelli's favorite choice, the producers decided to cast Tanya Roberts.
Sultan, the tiger that played "Ruh" in the movie, died about 2 years after the movie as a result of severe skin problems as well as other health issues caused by the toxic black dye used.
Several of the actors appear in very small costumes, including loincloth-only garb. Though the film appears to be set in a warm climate, it was quite cold on the set and the actors would have to find warmth in between scenes.
Don Coscarelli's original choice for the villainous role of Maax was Klaus Kinski, but an agreement could not be reached and the producers hired Rip Torn instead.