Title: "Eye for an eye" is a term used to refer to reciprocating inflicted injuries via an equivalent injury. For example, if one person pokes another in the eye, the latter pokes the former back. It is also part of a famous quote by Mahatma Ghandi "An eye for an eye only ends up making the whole world blind."
McMaster's is a play on the fast food restaurant McDonald's.
Danny's speech to Undergrowth, "As the duly deputized protector of Amity Park..." is possibly a reference to Doctor Raymond Stantz's speech to Gozer, "As a duly designated representative of the City, County and State of New York..." in the movie Ghostbusters.
The scene of Danny being revived in Frostbite's Realm is an allusion to the Hoth Echo Base in Star Wars Episode V: The Empire Strikes Back. Creator Butch Hartman's love of the movie series is well known, making several allusions to the movies in his cartoon series. Coincidentally, Mark Hamill (who played Luke Skywalker in the original Star Wars trilogy) does the voice of the evil Undergrowth.
Frostbite sometimes talks in "Object Subject Verb" format, similar to Yoda from Star Wars.
The green clothing Sam wore under Undergrowth's mind control the first time were reminiscent of Poison Ivy, a Batman villainess. Sam's later appearance as Queen is possibly a reference to Disney's Sleeping Beauty's villainess Maleficent. A further reference to this are the overgrown thorny vines that have taken over the city.
The name of Sam's Venus Flytrap "Demilo" is a pun on the famous statue "Aphrodite of Milos" better known as "Venus de Milo".
This episode is similar to the 1997 film, Batman and Robin where Danny has Ice power similar to Mr. Freeze's ray gun, and Sam being a plant queen like Poison Ivy.
Caption: Thinking outside the box means to go beyond obvious, cliche ideas and find originality.
When the Box Ghost releases snakes from Pandora's Box, Tucker shows his fear of snakes and cries out, "Why did it have to be snakes?" This is alluded from Indiana Jones' famous line in Raiders of the Lost Ark.
Several creatures, locations, and objects seen in this episode are based off of popular concepts from greek mythology, such as Argus Panoptes, Pandora, Pandora's Box, Pegasus, Cerberus, Hydra, Centaur, Minotaurs, and Cyclops.
When Danny starts the jet before going into the ghost zone, he says "atomic batteries to power, turbines to speed." In the 1966 Batman television series with Adam West and Burt Ward, that was what Robin said before the dynamic duo sped off in the batmobile from the batcave. The same line was featured in the Nickelodeon movie Jimmy Neutron: Boy Genius. Jimmy said it as he prepared to blast off in a homemade rocket.
The scene where Danny, Tucker, Sam, and Jazz using the Fenton Gadgets is a reference to Agent K and J stopping Edgar the Bug from the 1997 film, Men in Black.
This episode has a similar scene to the 1998 film, Deep Impact where the government sends a rocket to destroy a meteor and it fails.
This episode is similar to the Men in Black: The Series episode "The Endgame Syndrome", in which that all the ghosts, and everyone trying to avoid the meteor, is a reference to the MiB agents defeating the invading aliens.
This episode has a striking resemblance to the plot of the Nintendo DS game, Megaman Starforce 3 Black Ace/Red Joker, where the hero must stop an asteroid made with some unusual matter, and in the end, his secret identity is revealed to the whole world.