Peter Martell was cast as Cat Stevens but broke his foot at the beginning of the shooting and was replaced by Terence Hill, who met Bud Spencer for the first time.
First movie with Bud Spencer and Terence Hill in a Leading role together
Despite rumours to the contrary, the credited composer for this movie was a noted Spanish composer in his own right. Ángel Oliver Pina was born in Moyuela on 2 January 1937, died in Madrid 25 April 2005 and won numerous music awards including the Gran Premio di Roma in 1965. The notion that he was a pseudonym of veteran Italian composer Carlo Rustichelli is fairly absurd. Music publisher CAM's copyright catalogue (entry #517) registers the score to two separate composers, namely Carlo Rustichelli and Ángel Oliver Pina.