I'm a Zit
One of the most iconic images of the film is Bluto, played by the round-faced John Belushi, filling his cheeks with mashed potatoes and spitting them all over his lunch companions, telling them that he is pretending to be a zit. It is at once grotesque and humorous, and epitomizes the character's sophomoric (if creative) sense of humor.
Toga Party
The men of Delta throw a toga party at one point to cheer themselves up after getting scolded by Dean Wormer. It is a wild night in which most of the guests wear togas, clothes from ancient times that symbolize indulgence. The dilapidated frat is filled with college students dressed in homemade versions of the stately robe.
Marching band
As part of their prank to derail the homecoming parade, the Delta brothers take over the front of the parade and lead the marching band at the front of it down an alley. At the end of the alley is a brick wall, and the marching band continues marching towards it, running into the wall rather than changing course. The image is comical and absurd, representing the fact that the instrumentalists are lemmings, following the pack rather than making informed decisions.
Professor Jennings in class
When we first meet Professor Jennings, he is giving an unenthusiastic lecture about Milton's Paradise Lost. The sleepy-eyed professor, with a mustache and tweed suit, simply writes the word "Satan" on the board, and seems rather bored by the book, in spite of it being the topic of his lecture. This image shows that even the faculty members in Animal House are more interested in having a good time than taking life too seriously.
