In "Legends of Tomorrow" S03E17 ("Guest Starring John Noble"; 2018), the Legends noticed the demon Mallus (played by John Noble) sounded exactly like John Noble, so they time traveled to the set of LotR and gave Noble a fake script so they could record it and manipulate Mallus' followers.

In the Brazilian dub of The Flash S08E01 ("Armageddon, Part 1", 2021), audio was accidentally left in of Barry's voice actor saying "Look at this shitty dialogue" ("Ó que diálogo merda"). It's theorized this happened because the people behind the sound editing/mixing didn't speak Portuguese.

During the New 52/DCYou era, Barbara Gordon's Oracle identity could "never be used or even mentioned in any context, no matter [the writers'] intentions with it." Barbara was also forbidden from wearing glasses, being a librarian, and having a cool hideout.

In 2015, a mysterious armored man was spotted on the set of "Suicide Squad" (2016). Many thought he was a character in the movie, with Deadshot being a popular guess. He was just a Real Life Superhero guy who walked by.

According to the official timeline for the "Future State" (2021) event, Tim Drake is still Robin in big 2040.

Blue Beetle #3 (1964) featured a fan letter from 16 year-old George R.R. Martin. "The first issue of BB wasn't the greatest comic book I've ever seen, but it was the best stuff to come from your company. The plot of his origin story was excellent, and the tale itself was very good."

In The Flash S03E19 (2017), H.R. Wells and Cisco sing "Swing Low, Sweet Chariot". In the Latin American Spanish dub, they sing "Cha-La Head-Cha-La", the first opening theme of Dragon Ball Z, likely referencing the fact Mario Castañeda voices both Wells and adult Goku.

In Brainiac's first appearance (1958), he was accompanied by his alien pet monkey, Koko. In the Post-Zero Hour (1994) era, the Legion of Super-Heroes' Brainiac 5 also had his own Koko. The little guy is still remembered sometimes.

"Aquaman" #56 (1971), written by Steve Skeates, was intended to kickstart a new story arc, but the series was canceled on that issue. When Skeates wrote Warren Publishing's "Eerie" #37 & #40 (1972) and Marvel's "Sub-Mariner" #72 (1974), he used them as sequels to his Aquaman story.

On October 16, 2001, Smallville premiered on The WB (which later became The CW), following the coming-of-age adventures of a teen Clark Kent. Today, The CW airs the series finale of Superman & Lois, the final DC show on the network, following an experienced Superman and his family.

As you may know, the death of Robin (Jason Todd) in 1988 was decided via a phone poll. In 2014, Dennis O'Neil talked about a lawyer who voted 85 times by programming his Macintosh to dial the killing number every few minutes. "Robin Dies" defeated "Robin Lives" by a slim margin of 72 votes.