There are more such moments than we can explain here, but we've done our best to collect a few of the more obvious or intriguing tidbits. These details will mean little to those who have not seen the movies, but they can tell you what to look for when you do.
Zero
The entire opening sequence is a tribute to "A Kid Named George," one
of Zach's earliest and most popular videos.
The knocking sounds before Buffalo Man enters to kill Boy's parents
were not planned.
Buffalo Man was lowered and raised using a fishing pole.
Austin Robertson actually says two of Mortimer's lines, due to a recording
mistake.
In his hideout, Buffalo Man stands on the Bible, with a sqeegee behind
him.
Horrible and discordant "music" during the hideout scenes was the sound
of a piano being tuned.
The ginger beer Zach and Johnny drank before the final battle was weeks
old.
Boy missing Buffalo Man with his slingshot was a last minute decision.
Untitled
The voice at the end of the movie painfully saying "Oh my god" was
Johnny's girlfriend at the time.
Many of the Untitled trilogy's greatest supporting cast members must
forever go unnamed: the garbage man in I, the Coke Man
in U2, and the Old Lady Who Was Smoking in III.
At least half of the Untitled props were stolen from a church, including
Mortimer and Jaxine.
II
A failed eye-in-the-pyramid "Illuminati" symbol appears somewhere in
the background of the final battle.
All music used in the original versions of II and III were accomplished
by taping headphones to the camera's
microphone.
U2
Mortimer's weapon of choice is rolled up socks, originally used in
II because we didn't have anything for him to throw. An
expression of pain can be seen on Johnny's face in U2, as his donated
socks reveal bare feet to the searing dune sands.
Mortimer's armed robbery of Libby's bike during his crime spree coincided
with a large rash of bike thefts at the CSA.
In the Crystal View scene of U2, the guy says "So Kayli, I hear things
are heating up between you and Bob...", and she
replies "Horse!!"
When Mortimer is walking to the beach in U2, you can faintly hear the
words "Here is the goat" spoken when he is near the
middle of the screen.
A much clearer Illuminati symbol appears in the background of showdown.
III
When aliens attack the Crystal view, the owner wields a ketchup bottle,
as if to retaliate.
Assembly manager Jim Buzzel can be faintly seen in the distance at
the end of Jaxine's rampage. According to a common interpretation,
Jaxine was actually moving on to kill Jim before the shot ended.
The red filter used for Jaxine's rampage consisted of saran wrap and
permanent marker.
During the Mortimer/alien chase scene in III, the alien is played by
both Dave and Johnny.
A shortage of actors was the reason aliens disappear when they die.
In the final battle scene on the beach in III, Johnny plays both aliens
(and Lord Kuthumi).
Buffalo Boy momentarily appears during the battle between Mortimer
and Jaxine.
During the "final battle" scene of III, Lord Kuthumi actually broke
Mortimer's stick in half. For the rest of the scene, we
used Jaxine as his support, with her head under the sand.