Alternate Jingly Bells scene
Switch to animatics for the alternate scene of "Jingly Bells".
Go frame-by-frame when Gretchen is crying, seen just after the transmission of Tak pops up. As the camera zooms away from Gretchen, there is a transparent transition of 2 views of Tak and Dib talking.
Alternate "Attempt" scene
In the scene where Zim begins his numerous attempts to learn human 'affection', if one switches to animatics, one can see an alternate version.
At the part where Tak is describing her downfall on Devastis, you see her in front of an Irken Control Brain for a short time. On the Control Brain's main screen, a few clips from the very beginning of "The Nightmare Begins" can be seen, namely the ships that fly towards Conventia as the title appears.
Unveiling Tak's Plan
When Zim, Dib, and Gaz view Tak's plan in Zim's base, Dib's shirt is white and his ears are missing.
An alternate Hogulus canyon scene can be viewed when one switches to animatics.
A little movie clip that goes even when paused (go frame-by-frame).
Alternate escape scene (switch to animatics).
The paramedics in the back of the ambulance that take Moofy away are vampires (switch to animatics for a single frame).
During the 'awkward silence' scene, Zim's contacts are missing.
The comic book Jhonen's reading is an issue of "Happy Noodle Boy".