* ActorAllusion: The third season ChristmasEpisode is called in which Max believes an autistic child is communicating a message from his son is called "Samuel Rising." Miko Hughes, who appeared as an evil alien in three episodes of the second season, played the autistic child in the movie ''Film/MercuryRising''.
** In "Viva Las Vegas," Michael gives everyone drink themed aliases for their fake [=IDs=]. Alex, played by Colin Hanks, son of TomHanks, gets the alias Tom Collins.
* HeyItsThatGuy: Hey, it's [[GreysAnatomy Izzie Stevens]] back when she was a teenage alien! They even have the same first name!
** And those two guys from ''Series/CSIMiami'' and ''Film/DWar''... * crickets*
** And that vampire lady from ''Series/BuffyTheVampireSlayer'' and ''Series/{{Angel}}''
** Not to mention [[Series/TheWestWing Toby]]!