Despite denying the possibility of a cameo several months ago, Tom Ellis appeared as Lucifer on the latest installment of the Arrowverse's Crisis on Infinite Earths crossover event. Back in October, rumors swirled about the actor's potential involvement after a fan reportedly spotted him near the set. Ellis later addressed the rumors with an emphatic denial he would be on the show, referring to the possible cameo as a "hard pass" and insisting he had only been in town to visit with a friend for a birthday celebration.

Now, it's pretty clear Ellis was in fact just doing his best to keep the cat in the bag, as his Lucifer character made a surprise appearance on Tuesday evening's episode of the latest ArrowVerse crossover Crisis on Infinite Earths. The moment comes when Constantine (Matt Ryan), Mia (Katherine McNamara), and Diggle (David Ramsey) travel to Earth-666 for their quest to retrieve Oliver Queen's (Stephen Amell) soul. As Luficer, Ellis assists the trio with their endeavor, but not before making sure to put on the charm for both Mia and Diggle before the cameo ends. You can watch a clip of the full scene below.

Though many speculated that Tom Ellis would show up as Lucifer, the actor denied he would be participating in this huge crossover. He had this to say to Entertainment Tonight about the cameo.

"So yes, he is in the crossover. When I went to go and shoot the scene, we were talking on set beforehand -- myself and Matt Ryan -- and we were like, 'This is so exciting. Wouldn't it be amazing if we could keep this a secret for the fans until they actually see it onscreen that night?'. Of course, these days that's not that possible with social media at all. I think there were a few people hanging around the set who noticed that I was there and put stuff out that I was going to be in it, so I kind of was like, 'I would still really like to surprise some people.' So that is why."

The actor went onto say this about participating in the big crossover, honestly under the belief that it wasn't possible at first. Asked if it was an easy decision to jump on board, he says this.

"It was, actually. Yeah, it was. There were numerous reasons. One, when we started shooting, we did seasons one and two of Lucifer in Vancouver, so there is a big place in my heart for Vancouver. It was an opportunity to go back, see some friends and do all that sort of stuff. Also on the work side of it, we talked over the years about Lucifer being a DC character and, 'Is there any chance of this happening?' And I honestly thought there wasn't. So when they said [this idea], I was like, 'Yeah, no, let's do it. Let's do it,'" the 41-year-old actor said. "I know Matt a little bit as well and we've talked about it in the past, so we made it happen! Indeed, we manifested it!"

He goes onto say this.

"I hope [the fans] are reacting with pleasure! I mean, that's why I wanted to keep it a surprise because really, with all these characters that we do know that are happening in the crossover, we just wanted it to be something that would surprise and it would be a nice little Easter egg."

Tom Ellis also dropped an important piece of information. Apparently, this crossover takes place before his own standalone series. He goes onto explain.

"We're playing it as if it's in the five years before the show, Lucifer, started, so when Lucifer spent five years in L.A. before meeting the detective and all those things unfolding. This is him in his proper playboy, don't-give-a-damn-about-anything stage in his life. He is very irreverent with our characters when they turn up in the scene and obviously, with Constantine, there is some history there."

Finally, the actor was asked if he would ever think about returning to The CW's ArrowVerse in the future, with his own show about to come to a close with Season 5 on Netflix.

"That's a question for the DC bosses, not for me! I never say never. With these crossover episodes, it opens up a world in which they can really experiment with time and it felt like -- if there was ever going to be an opportunity, this was it, you know?"

Crisis on Infinite Earths brings together all of the CW shows which make up the continuity known as the Arrowverse. Supergirl, Batwoman, and The Flash have devoted episodes to the five-part series already, with Arrow and Legends of Tomorrow to follow in January. The crossover event has opened the door for many DC-based characters from separate movies and TV shows to appear, which has also included Brandon Routh (Superman Returns) and Tom Welling (Smallville) as different versions of Superman, Erica Durance (Smallville) as Lois Lane, Burt Ward (Batman) as Dick Grayson, and Kevin Conroy (Batman: The Animated Series) as Bruce Wayne.

As for Lucifer, the popular show is preparing for its upcoming fifth and final season on Netflix. Previously, the streamer saved the series after Fox gave it the boot in 2018 after three seasons. Lucifer season 4 premiered on the streaming service earlier this year, and it has since been confirmed the next season of the series will also serve as its last. Bringing the show back for just two more seasons still feels like it's coming to an end a bit too soon, but going this route is certainly preferable to leaving the series unconcluded after three seasons. As we've also seen with Crisis on Infinite Earths, Tom Ellis can always show up as the character in other projects as well.

Crisis on Infinite Earths will conclude with new episodes of Arrow and Legends of Tomorrow on Jan. 14, 2020 on The CW. Given how many amazing cameos we've already seen, chances are we'll be seeing some other surprises from the crossover event. Hopefully, we'll also be seeing more projects like this in the future, because each installment of this crossover series so far has been stellar. The Crisis on Infinite Earths scene with Lucifer's cameo shown above comes to us from the YouTube channel TV Promos.