When it was first announced that Legendary was partnering with The Pokémon Company to make a live-action feature film adaptation of Detective Pikachu , the Internet came together with a singular demand: Let Danny DeVito voice the eponymous electric gumshoe . These DeVito devotees originally set the Internet ablaze prior to the Detective Pikachu video game’s North American release in 2016, and the announcement of the feature film grew their ranks and amplified their voices.

In a 2016 Q&A at the Paley Center in Los Angeles, DeVito revealed that he had no idea what Pokémon even are, but that didn’t discourage fans from editing his voice into trailers and holding out hope that those Hollywood bigwigs would see the light and cast the beloved 74-year-old as an even more beloved yellow mouse. However, neither the hundreds of tweets nor the 51,144 signatures on a Change.org petition (which was sent to Game Freak and Nintendo of America in order to lobby for DeVito as the official in-game voice of Detective Pikachu in the English dub) were enough to make their dream come true; the role ultimately went to Deadpool‘s Ryan Reynolds, who is bringing a unique form of method acting to what can only be called the role of a lifetime.

But Danny DeVito fans have cause to rejoice, because for a brief moment in time, their shining star did provide the voice of Detective Pikachu. While it will never see the light of day and it was purely for fun, Nerdist has learned that the visual effects team used Danny DeVito’s voice from shows like It’s Always Sunny in Philadelphia while testing Detective Pikachu’s animation and to assist with the casting process.

While visiting the set of Detective Pikachu at Shepperton Studios outside of London, Nerdist and other media outlets spoke with visual effects producer Greg Baxter, who revealed this delightful detail about the filmmaking process.

“We knew what the character was gonna be—you know, what it looked like, the size, the shape, even some of the basic movements,” Baxter said. “But then as we were looking at different actors, we would put voice from what that actor had done in the past through Pikachu just to see how that was gonna play. And something really magical happened when we put Ryan Reynolds’ voice into Pikachu.”

He continued, “It’s just not at all what you’d expect and it’s just funny, because … the way he speaks and the way he acts is almost like one giant run-on sentence. He keeps talking until jokes just fly out. And for this little, cute, little thing to have that kind of crass and sarcastic sense of humor and then just kind of keep going … that actually affects the animation.”

Seizing on this crucial detail, we pressed him for clues as to which other celebrity voices they tested. Initially, Baxter was reluctant to respond, telling us that he “plead[s] the fifth,” and assuring us that “there were many” options and that they “tried a range of characters.” However, when specifically asked about Danny DeVito, Baxter finally admitted the truth.

“Yeah, we threw some of his … Always Sunny in Philadelphia … in as well,” Baxter revealed. “I mean, we really tried a range of actors. Different pitches, different sounds of voice, different … big, small, everywhere in between. And really, once you put a voice to an animated character, something just amazing happens, not what you expect. But once Ryan went in, it was kind of game over. That was amazing.”

So there you have it, folks: the words “Rum Ham” may or may not have come out of an eerily lifelike Pikachu’s mouth at one point or another. In the meantime, maybe we can convince the powers that be to cast Danny DeVito as Meowth if they ever deign to do a live-action adaptation of the adventures of Ash, Misty, Brock, and the gang.

Detective Pikachu hits theaters on May 10, 2019. Stay tuned for more inside scoops from our time on the film’s set!

Images: Warner Bros./Legendary

Editor’s note: Nerdist is a wholly owned subsidiary of Legendary Digital Networks.

This article was updated on Tuesday, March 19 to clarify when the first petitions for Danny DeVito to voice Detective Pikachu started and to whom the Change.org petition was directed. Special thanks to Anime News Network’s Lynzee Loveridge for spotting.