After failing the rescue attempt of a raccoon in the Himalayas (a parody of the opening to the film Cliffhanger), Ace Ventura undergoes an emotional breakdown and goes on a personal soul-searching quest by becoming a Tibetan monk. He is approached by Fulton Greenwall, a British correspondent working for a provincial consulate in the fictional African country of Nibia. Being that Ace's influence is disruptive to the monastery, the Grand Abbot eagerly gives Ace excuses by which to justify his departure.

Greenwall asks Ventura to find a sacred animal called Shikaka, which has become a point of contention. Shikaka, which is a great white bat, is a sacred animal for the Wachati and Wachootoo tribes of Nibia, a fictional African country; whenever its name is spoken, the tribesmen must bow. Accompanied by his capuchin monkey, Spike, Ace travels to Africa and returns to his pet detective work.

After arriving in Nibia and meeting with the head of the consulate, Vincent Cadby, Ace begins learning about his case as well as the possible suspects. Ace, normally an animal lover, must overcome his chiroptophobia (fear of bats) in order to continue studying the case. He travels to the Wachati tribal village, where he learns that Shikaka is meant as a wedding present from the Wachati Princess, who is set to wed the Wachootoo Prince. If the bat is not returned in time, the Wachootoo will declare war on the Wachati tribe instead. Much of Ace's activity involves eliminating various suspects and enduring the problems of dealing with the Wachati and the Wachootoo, who refer to him as the "white devil". This proves difficult, and is made more so by other incidents including attempts to kill him.

Reduced to the limit of his ability to solve mysteries, Ace consults the Grand Abbot via astral projection. Advised by the Abbot, Ace finally discovers that Vincent Cadby had taken the bat and hired Ace as a cover for his own crimes. Cadby plans to let the tribes destroy each other and take possession of their land, using the numerous bat caves containing guano to sell as fertilizer. Ace manages to thwart Cadby's plans. However, tribal security chief Hitu is by Cadby's side and sends him to jail, but Ace calls an elephant to escape, and then summons herds of animals, crushing Cadby's house. He tries to shoot Ace with a shotgun, but he is knocked out by Greenwall's fist. After waking up, Cadby manages to escape, with the bat, in a car and Ace chases him in a monster truck. Ace throws the truck's cigarette lighter at Cadby in an attempt to distract him, who finally rams into a tree and the cage with the bat flies away. Ace runs over Cadby's car, while Cadby runs away.