While most of the time post-credits scenes are used to set up the next movie in a franchise or film series, like in the Marvel Cinematic Universe films or Bad Boys for Life, some movies just have scenes added to the end for no other reason than to make the audience laugh, or sometimes wrap up a loose end. In the case of Dolittle, the new movie starring Avengers: Endgame's Robert Downey Jr., the post-credits scene tacked onto the end is an example of the latter.
There's no way that Dolittle will be getting a sequel, seeing as it stands to lose upwards of $100 million at the box office, so teasing another installment is certainly out the window. However, if you do happen to see the movie and stick around through some of the credits, you'll see a short scene that reveals the fate of one of the film's characters.
In the movie, actor Michael Sheen plays a character named Dr. Blair Mudfly, one of the film's antagonists and the main foil for Downey's Dr. Dolittle. Mudfly and Dolittle have a history, having gone to school together and become rivals. Mudfly consistently mocks Dolittle for his methods and love of animals, and is tasked with stopping the hero from getting the ancient hidden fruit that will save the life of the Queen of England. When Dolittle and Mudfly both reach the lair of the dragon, Mudfly is cast aside, seemingly never to be seen again.
However, we do see the villain one more time, in the scene attached to the credits. Mudfly is seen down in a cave by himself, and it doesn't look like he has any way out. He then sees a bat and tries to talk to it, the same way Dolittle had throughout the entire movie. As you can probably guess, that doesn't work out. An entire horde of bats opens their eyes and stares and Mudfly, before they all fly and attack him at once.
It's a silly scene that doesn't add much to the movie, but it does help to offer some closure regarding Mudfly's whereabouts.
Dolittle is now playing in theaters.