The Pre-After-Credits Scene
Because this is Deadpool, there's a scene before the actual post-credits scenes start in which the Merc with the Mouth and Fred Savage talk about how much they love the stingers. The latter is a fan because it "feels so private" to be sitting in a theater that everyone else has walked out of.
The original after-credits scenes then play for any younger fans who missed them the first time.
Fred Savage's Escape
Pretty much all the new footage in Once Upon a Deadpool are the scenes with Fred Savage so it probably won't surprise you to learn that we return there for a mid-credits scene which sees Wade Wilson finally cut him free after holding the Princess Bride star captive for the past three days.
His legs are still duct taped together so he struggles to walk away, but the Merc helps him through the bedroom door and the camera then pulls back to reveal the movie crew.
Stan Lee Tribute
Stan "The Man" Lee may not have created Deadpool but he's played an important part in the franchise, making a cameo appearance not only in both movies but even the first
Deadpool 2 teaser.
After the credits have played, we get to see some outtakes from that teaser as Stan tries out different lines like "Isn't your suit supposed to be green?" and "Wow, it's Ryan Gosling!" Then, a short tribute to the legendary comic book creator plays as he talks about the characters he created and how great it is to see them being so popular.
It ends with Lee saying, "We wrote some good stories" and the whole thing is a truly touching tribute.