The mug shot of Kent Brockman in segment 2 parodies the mug shot of Nick Nolte that went viral in 2002 when he was arrested for driving under the influence on a California highway.
The bobble head doll of Jim Halterman that Bart shows the alien is based on a real car dealer, Jim Halterman Automotive of East Stroudsburg, Pa.
Kodos has been referred to as both male and female. In E.T. Go Home, Kodos mentioned her "700 testicles". However, Kodos was referred to as female in Treehouse of Horror VII, though this may be due to humans being unable to tell male and female Rigellians apart. Also, in Treehouse of Horror XXII, Kamala, a female Rigellian, also made a reference to having testicles. Kodos is not as feminine as Kamala.
In Mr. and Mrs. Simpson, Mr. Burns establishes Homer's weight at 241. This is similar to his weight in other episodes, which usually is as low as 239.
In E.T. Go Home, Bart shows Kodos his toys. He lists off a number of toys shown before, including Linguo, Sgt. Activity, Funzo, and, of course, Krusty.