Curiosidades

Bud Spencer, who is nearsighted, accidentally punched Joe Bugner unconscious during the filming of their big fight scene. Spencer miscalculated the distance of a right hook he was supposed to throw and his fist caught Bugner's jaw with full force.

The song "Grau Grau Grau" was actually sung by Bud Spencer. In the English language dub, this is the only time Spencer's voice is left intact, his thick Italian accent coming through very distinctively.

Thirteenth movie collaboration of Italian comedy duo Terence Hilland Bud Spencer.

Apparently, the movie was modeled on being a comic version of the then recent African adventure movies África Express (1975) and Safari Na Africa (1976).

Fourth and final collaboration of producer-director Italo Zingarelli and the comedy team Terence Hill and Bud Spencer. Zingarelli had been the producer of the duo's successful "Trinity" movies "My name is Trinity" [Trinity é o Meu Nome (1970)] and "Trinity is still my name" [Trinity Ainda é Meu Nome (1971)] as well as "All the Way Boys" [Dá-lhe Duro, Trinity! (1972)]. "Im for the Hippopotamus" was the only picture that Zingarelli directed the both of them. Zingarelli also produced Spencer's "Five Man Army" [Exército de 5 Homens (1969)] in which he also directed the Italian version.