The Sandman spin-off show creator reveals that Netflix asked for Easter eggs and Neil Gaiman created a new character for the series

gamesradar.com:

New supernatural TV series Dead Boy Detectives, based on the DC Comics of the same name by Neil Gaiman and Matt Wagner, has had an interesting journey to our screens. Originally starting out life as a spin-off to HBO Max's (now just Max's) superhero show Doom Patrol, in 2022 the streaming service gave the production a series order with The Flight Attendant's Steve Yockey attached as showrunner. Only a year later in February 2023, the new show moved to Netflix as it was no longer compatible with James Gunn and Peter Safran's plans for the new DCU.

In a way the shift has worked out for the best though as the series is now a spin-off from Netflix's 2022 hit The Sandman, which is based on the comic books where the Dead Boy Detectives themselves first made their debut. Leading duo Edwin Payne (George Rexstrew) and Charles Rowland (Jayden Revri), who are best friends that decide to ditch the afterlife to solve crimes involving the undead on Earth, first appeared in The Sandman #25 in a story that tells the tale of how they met. 

Now that the new series was taking place in the world of The Sandman, showrunner Yockey could have some fun with making connections between the two. As he tells SFX magazine in the new issue, which features Doctor Who on the cover, Netflix actually actively encouraged him to include more references for fans. He teased: “Netflix encouraged us, even though we were already in production, to find some Easter eggs, some surprises, that because we’re on the same network we’re now allowed to include that we weren’t allowed to include before. I would obviously love to continue to cross-pollinate, where it makes sense, with Sandman.”

That's something Gaiman himself is more than happy to oblige with - in fact, as Yockey also reveals to SFX, he even created a brand new character for the show, someone who works in the afterlife's lost and found department (keep your eyes peeled). As the showrunner states, the author has been a supportive presence throughout