The Walking Dead included a Breaking Bad Easter egg on its newest episode, but unless you were looking for it, you probably missed it. In the episode, the backstory was provided for Alpha, the leader of the sinister new group of flesh-wearing marauders called the Whisperers. As revealed in the show, Alpha used to sing a certain song with her husband Frank to their daughter, Lydia. Appropriately, the song was "Lydia, the Tattooed Lady." On Breaking Bad, there was also a character named Lydia, and diehard fans might remember that in the show's series finale, Todd used the same song for her ringtone.

There have been multiple subtle references to Breaking Bad on past Walking Dead episodes as well. Perhaps the most famous of these Easter eggs came in Season 2, when Daryl revealed his brother Merle's stash of drugs had some of Walter White's trademark blue meth inside. Daryl later told a story to Beth Grimes about a drug dealer who was described as a "janky little white guy," who said to Daryl, "I'm gonna kill you, bitch." That description sounds dead-on for Jesse Pinkman, floating that idea that the man Daryl was referring to and Jesse were one in the same. Could it even be that, somehow, Walter's special blend of meth eventually resulted in the zombie apocalypse seen in The Walking Dead?

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Of course, Breaking Bad is far from the only other franchise to be recognized by Easter eggs on The Walking Dead. Many iconic zombie movies and horror films have also had on-screen tributes make it into the series. Notable zombies from classic George A. Romero movies like Dawn of the Dead and Day of the Dead have had "cameos" on the show, looking exactly as they did in the movies. The crate from a segment in the original Creepshow movie is also shown hidden away in the foreground of a scene. Walking Dead EP Greg Nicotero had visited the Creepshow set during production, and is now spearheading a TV series based on the movie for Shudder, so it seems likely that particular Easter egg was his work.

Season 9 of The Walking Dead has been very well received with fans and critics, despite the show's overall falling ratings. New showrunner Angela Kang came on board at the start of the season to replace Scott M. Gimple, and the quality of the series has seen an upswing under her watch. Unfortunately, with several major players like Andrew Lincoln, Chandler Riggs, and Lauren Cohan leaving the series, trying to restore fan interest could be an uphill battle. It certainly doesn't help matters that Danai Gurira has decided to end her run as Michonne on the show as well.

Breaking Bad is in the midst of having an official sequel movie made, continuing the story established by the show. Aaron Paul will reprise the role of Jesse Pinkman for the movie, and it seems likely Bryan Cranston will have some sort of cameo in a flashback scene. For more of The Walking Dead, you can catch new episodes when they air Sunday nights on AMC.