A lion named King who starred in the movie was shot during filming by a policeman who thought that the lion attacked a teenager. In reality, the teenager was bothering the lion who in turn went and knocked the teenager off his feet, as he was taught to do for the movie.
The film was produced to cover Dino De Laurentiis's outstanding debts to Mosfilm studios for services rendered to the production of Waterloo (1970).
Producer Dino De Laurentiis was not committed to the film, to such an extent that he tried to cut the living expenses of the large Russian crew while shooting on location in Italy. He also demanded that a very small number of takes be shot to reduce lab bills. This resulted in the crew going on strike. He also vetoed the casting of big name Italian stars such as Alberto Sordi, Marcello Mastroianni, Claudia Cardinale and Sophia Loren. This decision backfired when the finished film was presented to Paramount for a possible distribution deal. The Paramount bosses told De Laurentiis that the film could have been a great international success if well-known international stars had been cast.