The smokin' hot Thalia Menninger returns for a visit and Dobie decides to make her the beneficiary on his life insurance policy. Then he becomes paranoid that she's trying to kill him.
Dobie signs himself and Maynard up for an expedition to the Amazon in order to follow a hot chick. Once there, Maynard gets made chief of a tribe of cannibals.
In the college animal behaviour laboratory, Maynard is assigned to develop the talents of a chimp. If he doesn't succeed the simian might meet a terrible fate.
In yet another plan to snare Dobie, Zelda announces she's going to marry Maynard figuring that Dobie will do anything (such as take his good buddy's place) to save him from such a fate.
Maynard swallows some energy pills which give him superhuman strength so Herbert decides he should enter the boxing ring with the elder Gillis as his manager.
Dobie falls for the smokin' hot younger sister of Dr. Burkhart but according to family tradition she must wait until her older sister gets married first.
