The R-rated Marvel superhero calls the actor that plays him a "rich man's version of my most recent turd."
"Please, guys, no one stand up. It’s CBS, I know how old your audience is," Reynolds said, after walking into Colbert's monologue and taking a bow.
After the late-night host introduced Marvel's sassiest superhero, the Merc with a Mouth offered to be Colbert's guest -- but that slot was filled already by Jamie Foxx. "I see, well he's got boyish charm for days. I for one loved his work in 'Back To The Future,'" Deadpool joked before Colbert corrected him, "That's a different Foxx."
"I'll tell you who should not be on your show," Deadpool said. "Ryan Reynolds, huge asshole. He's like the poor man's version of Ryan Reynolds, and like the rich man's version of my most recent turd."
Colbert had enough and told Deadpool that it was time for him to leave, in which the superhero agreed. "You're absolutely right Jimmy. I should go -- I should go ahead and read the rest of your monologue."
"Oh really, you think you can do this? Both stand and read jokes?" the late-night host asked. "In our own way, we late-night hosts are basically superheroes."
"Because you’re all mostly white men?" Deadpool fired back before turning his attention to the teleprompter filled with jokes about one of Colbert's favorite political targets, President Donald Trump.
"The administration is still dealing with the fallout announcing that the U.S. will be pulling out of the Iran deal," the red-suited hero said in the monologue. "It's Trump’s biggest pulling out blunder since Eric."
Deadpool also mocked Trump’s latest Twitter rant on leaks in the White House. "We all know Trump prefers his leaks in Russian hotel rooms."
Reynolds' wife, Blake Lively, even got a shoutout toward the end of the bit, which concludes in the best way possible. If you've seen "Avengers: Infinity War," at least.
"Deadpool 2" hits theaters this Friday.