This Fall, four of the CW's DC Comics-based series -- Supergirl, Arrow, The Flash and Legends of Tomorrow -- will collide once again for an Arrowverse crossover of epic porportions. And based on a tease from executive producer Marc Guggenheim, it seems the "Invasion!" follow-up will introduce yet another DC hero to the shared small-screen superhero universe.RELATED: What Worked – and Didn’t – About the Arrowverse Invasion! CrossoverWriting on Twitter, Guggenheim teased, "Another Arrowverse Crossover tease. The Legends hour of the crossover officially begins prep today." He included an image of a mask that looks awfully familiar to fans of the Golden Age-era Justice Society of America...

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While we don't know for sure who the mask belongs to, it closely resembles the one worn by the Golden Age Sandman, Wesley Dodds. Not to be confused with the '80s Neil Gaiman Sandman, the mask looks like the one worn by the original Sandman who debuted in 1939.

A classic noir hero, Sandman is equal parts philosopher, chemist and detective. The character is fair at best in hand-to-hand combat, but using his keen intellect and knowledge of chemistry, Dodds is an effective crime-fighter. A master inventor, Dodds uses a gas gun that puts people to sleep — effective, if you're on a team that refuses to kill...

After appearing on his own and alongside his Justice Society of America teammates throughout the '40s and '50s, Dodds fell to the wayside as DC Comics made way for its Silver Age heroes. Dodds would later go on to star in the popular '90s comic book series Sandman Mystery Theatre. Published between 1993 and 1997, the 70-issue series -- from writers Matt Wagner and Steven T. Seagle, and artists Guy Davis, John Watkiss and R.G. Taylor, among others -- the fan-favorite series was told in a film noir fashion, chronicling the late-30s exploits of Dodds and his girlfriend, Dian Belmont.

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Whether or not the mask belongs to Dodds is up in the air -- we'll have to wait until the next Arrowverse crossover airs this Fall for further answers...

This year’s Arrowverse crossover will begin Monday, Nov. 27, with back-to-back episodes of Supergirl and Arrow, followed Tuesday, Nov. 28, by The Flash and Legends of Tomorrow. The event sees Arrow move from its new Thursday time slot to Monday for one week only.