Croquet

Croquet has never been a major plot point on the Simpsons, but games and equipment therefrom have made appearances from time to time, especially in later seasons.

Croquet Games

 * When Homer is exiled to a mysterious island when  his website accidentally stumbles upon a conspiracy, one of the ways he passes the time is with a game of croquet. (Season 12's The Computer Wore Menace Shoes)
 * When Marge envisions Protestant Heaven, she sees halo-festooned Protestants playing badminton and croquet. One of the croquet-players explains to her how things are different in Catholic Heaven. (Season 16's The Father, the Son and the Holy Guest Star)
 * When the family has a surplus of peaches, one of the activities in which Bart and Lisa engage is a game of croquet played with the fruit instead of balls. (Season 22's The Great Simpsina)
 * The more posh aliens restricted to District 10 play croquet instead of huddling around trash-can fires, as they do in District 9. (Season 23's Holidays of Future Passed)

Croquet Equipment

 * When Homer is called away in the middle of the night by his new boss Carl, there is an abandoned croquet game set up in the front yard. Marge is so angry at him leaving that she hurls a croquet mallet at him, though she misses and hits Ned Flanders instead. (Season 21's The Devil Wears Nada)
 * One of the many pieces of sports equipment used by Homer and Bart is a croquet mallet. (Season 21's Judge Me Tender)
 * When the crew of their erstwhile cruise ship put the Simpsons on trial, the judge uses a croquet mallet en lieu of a gavel. (Season 23's A Totally Fun Thing That Bart Will Never Do Again)