SPOILER WARNING: This article contains major spoilers for "Crisis on Infinite Earths, Part 1," the first installment of this year's Arrowverse crossover.

With the premiere of the newest episode of Supergirl, The CW's "Crisis on Infinite Earths" crossover event is officially underway. And it certainly didn't waste any time in getting to the highly-anticipated cameos featuring stars from DC's on-screen past.

The very first DC alum to reprise their classic role for "Crisis" was none other than Robert Wuhl -- who played Gotham Globe reporter Alexander Knox in director Tim Burton's 1989 Batman film. During an opening montage, Knox is revealed to still be residing in Gotham City on the aptly-named Earth-89.

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In his brief scene, Knox is seen reading a newspaper, the headline of which reveals Batman recently captured the Joker. Wuhl's character then lowers the paper, revealing his face, before looking towards the sky, which has turned an ominous shade of red. It is at this point Knox notices the Bat Signal, before muttering, "I hope you're watching, big guy."

Wuhl's involvement in "Crisis" was first reported back in October, though was never confirmed until now. What's more, the initial report proved to be exactly right, describing a scene in which Knox is seeing reading a newspaper before looking towards the sky.

"Crisis on Infinite Earths, Part 1" marks the second-ever on-screen appearance of Alexander Knox. Up until now, 1989's Batman was the character's only time appearing in live-action. The character was created specifically for Burton's film, and had not appeared in any DC comic books prior. With Earth-89 apparently in the Anti-Monitor's crosshairs, it's uncertain if Knox will return for a third appearance.

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"Crisis on Infinite Earths" begins Sunday, Dec. 8 at 8 p.m. ET/PT on Supergirl, then continues in Batwoman on Monday, Dec. 9 at 8 p.m. ET/PT and in The Flash on Tuesday, Dec. 10 at 8 p.m. ET/PT. After the winter hiatus, the crossover will conclude on Tuesday, Jan. 14 in Arrow at 8 p.m. ET/PT and in DC's Legends of Tomorrow at 9 p.m. ET/PT.