Fiend is Like Friend Without the 'R' - S1-E4
Trivia: Nergal is the villain introduced in this episode. "Nergal" originally was the name of the Babylonian God of Fire and Guardian of the Underworld. In the Bible, he is one of the demons allied with Satan himself. In the series Nergal is associated with the underworld and fire.
Trivia: They used real wolves (no CGI) to play opposite Bill Compton in the last scene of this episode.
Trivia: The season five episode "Independence Day" featured Chris Bruno's brother Dylan. The episode itself was Chris' first time as a director.
Trivia: There are a lot of Greek references. Cerberus, Tartarus, a messengers boots (Hermes reference) and the princesses. Twilight is the Greek word for friend love, or Philia. Cadence is Eros, or romantic love. Celestia is Agape, the love God has for mankind. Well, Celestia is kind of a god. Luna is Storge, love of a mother and child. This works because she has helped Scootaloo and Sweetie Belle in a motherly way. She was a mentor to both of them.
Trivia: **SPOILERS** When the demon takes over Ciri's body she dreams about being back at the party her grandmother had at their castle, and she sees her grandmother, Mousesack, her mother and her father. When she starts to question if it's really her grandmother, Mousesack and her mother all turn to ash and blow away. If you pay attention, you'll notice that her father does not turn to ash which is a foreshadow for later when it's revealed that he is in fact still alive.
Trivia: The music used for the Octopus Dare computer game is an 8-bit rendition of the show's main theme tune.
The Return of the Beast: Part 1 - S1-E1
Trivia: When we see the flashback of the accident that caused Bruce Banner to become the Hulk, at first we see the Hulk colored gray and then slowly turn green. This is a reference to the comics, in which the Hulk was gray in his original appearance.
The Scorn of the Star Sapphire! - S3-E5
Trivia: After freeing Miss Taylor from the grip of Star Sapphire, Green Lantern encases her in a green energy box and flies her away. The box is shaped almost exactly like a shuttle craft from Star Trek. (00:15:50)
Trivia: The Tall Knight is played by Peter Mayhew, best known for portraying the Wookiee Chewbacca in the "Star Wars" movies.
Through the Rabbit Hole - S2-E1
Trivia: The boy's comment, "Everybody is kung fu fighting" at the ruined school dance, refers to Carl Douglas' song of the same name from 1974, two years before this episode takes place, following the fledging martial arts craze in America. This song has recently (in a slight variation) resurfaced in Kung Fu Panda.
Trivia: When the Girardis are debating over what to watch for movie night, Will suggests one of the Godfather films. Joe Mantegna previously had a supporting role in The Godfather Part III.
Trivia: The cast were sworn to secrecy to not reveal the big twist at the end of season one. Reportedly, all the cast members were really good at keeping the secret... except Ted Danson, who couldn't help but give away the twist anytime he tried to explain the show to someone.
The Big Question / The Big Answer - S3-E11
Trivia: At one point in this episode, Hefer says "please put me down Mr. Crabs." Most of the crew from this show went on to make SpongeBob SquarePants a few years after Rocko ended, which has a character named Mr. Crabs.
Kiseki no fukkatsu! Yuyo no cosmo - S1-E5
Trivia: When Seiya falls down during the victory celebration and the three kids scream (the shot that comes before the one where Miho drops the picture) you can see briefly in the audience between the kids an easter egg appearance of Magical Princess Minky Momo, a character from a different anime. (00:13:50)
Trivia: The series was cancelled before the kids were able to learn who Ghostwriter was in his previous life. Producer Kermit Frazier revealed in 2010 that Ghostwriter was a runaway slave during the Civil War who was hunted down and killed while teaching other runaway slaves to read in the woods, and that his soul became trapped in the book that he emerged from Jamal's basement.