Yes, in Super Mario Bros. there will be a post-credits scene

It’s become common in movies to tease what happens next at the end of the credits, and it looks like the upcoming Mario movie will be no different.
In an interview with CBR, Mario voice actor Chris Pratt mentions that Nintendo fans can look forward to a post-credits scene that potentially teases what could happen after a Mario movie…
“Look, there’s a post-credits shot at the end of the movie that gives you an idea of what the sequel could be about. And that made me very, very excited.”
Pratt even referred to a recent conversation about the Luigi’s Mansion movie and thought “that would be great.”
Whatever the end of this post-credits scene, again, this won’t be the first time we’ve seen something like this. Besides the fact that it happens in every Marvel movie these days, it also happens in another film adaptations of video games such as Sonic the Hedgehog with some of the key characters revealed.
There hasn’t been any official mention of a Mario Movie sequel yet, but fellow Mario Movie star Seth Rogen recently said he’s also ready for new adventures – referring to a possible Donkey Kong spin-off.