‘Lanterns’ Just Hid a Major Batman Villain Easter Egg in Plain Sight

HBO’s Green Lantern series has kept audiences hooked with its slow-burn small-town mystery, but the show has also been quietly doing something else beneath the surface. While Hal Jordan and John Stewart chase down cosmic secrets in Rushville, Nebraska, eagle-eyed fans have started spotting hints connecting the series to a much bigger corner of the DC Universe.

That connective tissue has become one of the more intriguing subplots of ‘Lanterns’ discourse online, especially since Batman himself has yet to appear anywhere in James Gunn’s rebuilt DC Universe. Rather than waiting for an actual Caped Crusader cameo, the show has instead leaned on background details sharp-eyed viewers can piece together themselves.

Lanterns hides a major Batman villain Easter egg in plain sight, and possibly two, according to Polygon. The nod centers on Janus Cosmetics, a brand that’s popped up multiple times across the show’s first three episodes, and its ties to one of Batman’s most recognizable rogues.

In the comics, Janus Cosmetics is owned by Roman Sionis, better known as the Gotham City crime lord Black Mask. The company’s history involves a disfiguring, rushed-to-market waterproof makeup product that plays directly into Sionis’ comic book origin, making its appearance in ‘Lanterns’ feel far from coincidental.

The reference first surfaced in the show’s premiere episode, where a Janus Cosmetics poster appears behind John Stewart, played by Aaron Pierre, featuring a woman’s face partially obscured by black feathers. That imagery lines up with Sionis’ backstory as detailed in his 1985 comic debut, and it’s since resurfaced again in Episode 3, “OutKast,” suggesting the show isn’t done building on the reference.

What makes the connection even more notable is that it isn’t isolated to just ‘Lanterns.’ The Sionis name has also turned up in set photos from ‘Clayface,’ DC Studios’ upcoming theatrical release, where signage for Sionis Industries, the parent company behind Janus Cosmetics, was spotted during filming. That overlap ties two very different corners of the new DC Universe together through the same fictional business empire.

Black Mask isn’t new to live-action audiences. Ewan McGregor played a version of the character, Roman Beauvais Sionis, in 2020’s ‘Birds of Prey,’ though that film exists outside James Gunn’s current DC Universe continuity. Other projects like ‘Gotham’ and ‘Batwoman’ have also featured their own separate takes on the character over the years, meaning any new version introduced through ‘Lanterns’ or ‘Clayface’ would mark a fresh continuity entirely.

Whether this shared branding means Black Mask himself is heading toward live action within the DCU, or whether the Sionis name is simply being used as connective background lore the way Gunn has done elsewhere, remains unconfirmed. Either way, it’s a clever bit of world-building that rewards close viewing without derailing the show’s central mystery.

With ‘Lanterns’ still airing weekly and ‘Clayface’ still in production, fans now have two ongoing DC projects worth watching closely for any further Sionis-related breadcrumbs. Given how deliberately the reference has been placed so far, it feels unlikely to be the last time Janus Cosmetics shows up on screen.