Catch-22 - Homer refers to the punctured keg of beer as being “so cold...so cold.” These are the words Snowden uses when hit and bleeding, in the novel Catch-22. Milhouse also says these words in the season seven episode "Home Sweet Homediddly-Dum-Doodily" after Bart complains that nothing happened to Milhouse after playing with the monkey in the Pier One wicker basket.
Annette tying the licorice into the message "Do Me" is based on the trick of tying a cherry stem into a knot with one's tongue.
The Octuplets' first words are "Mommy, will you let daddy come back" and "Cookie".
In Homer's dream about Apu's infidelity, Apu calls him a eunuch. When he wakes up and looks up "eunuch", Homer screams. A eunuch is a castrated male or a female who finds neither men or women sexually attractive (these days referred to as "asexual").
Homer also looks in the "U" section of the dictionary when searching for the word eunuch.