The entirety of the "The Family Dog" chapter: To summarize, Fudge, for no apparent reason, refuses to eat anything. Later on, as the title states, he starts acting like a dog, only eating food when it's on the floor. The family decides to play along with it, but it eventually escalates.
Anne naturally starts freaking out when Fudge refuses to eat. Peter tells her to leave it be and Fudge will eat when he's hungry. Anne ignores him and takes Fudge to a doctor... who tells her the same thing. Peter points this out and adds that he did it for free. His mother continues to ignore him and takes Fudge to two more doctors until one tells her what she wants to hear (i.e., that she should make Fudge his favorite foods and give him whatever he wants in order to get him to eat).
And it all finally comes to a head that night when Anne makes him lamb chops. Fudge refuses them and Warren is coming to the end of his rope, telling Fudge that "The next time you won't eat something, you'll wear it!". Fudge demands cereal instead. Fudge then refuses to eat the cereal. His father marches him to the bathtub and upends the entire bowl of cereal over his head. Although this may border on child abuse due to Values Dissonance, it's still pretty funny. Also counts as a Moment of Awesome.
Later on, at a hamburger restaurant, Fudge shouts "Eat it or wear it!" and dumps a bowl of peas over his head.
When Fudge is showing off Uncle Feather, his pet mynah bird, to his former kindergarten class, he informs the uptight Mrs. Hildebrandt that Uncle Feather can speak French.
Mrs. Hildebrandt, to the bird: Oh, parlez vous Francais?