As the fallout from "Crisis on Infinite Earths" continues to impact the Arrowverse, the crossover's showrunner Marc Guggenheim reveals one team-up he wanted that was denied.

In an in-depth postgame interview on the crossover with the weekly podcast Fake Nerd Podcast, Guggenheim revealed he had really hoped for a meeting between John Constantine and Swamp Thing, given that the occult magician was initially introduced as a supporting character during Alan Moore's iconic run on the series. However, without specifying the rationale, Guggenheim's request to put the two characters was denied.

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"That was a really important inclusion for me. I did want Swamp Thing to be a big part of the crossover, because -- if you've got Constantine -- to not have Constantine and Swamp Thing together is a missed opportunity," reflected Guggenheim. "I'll just say that, for a variety of different reasons, I couldn't make that happen."

Swamp Thing had starred in his own short-lived DC Universe series, cancelled upon the series' premiere this past May, reportedly due to budget concerns linked to its primary filming location in North Carolina. The character briefly appeared in a silent cameo in the crossover's closing montage, languishing in the dark depths of the bayou. As for Constantine, the sly occultist continues to play a prominent role in the Arrowverse starring in Legends of Tomorrow.

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"Crisis on Infinite Earths" is available to stream in its entirety through The CW App.