Monty Python's Flying Circus did this. According to TV Tropes:
Credits Gag: In addition to many Creative Closing Credits, the placement of the credits in the show's sequence was a gag in itself.
Of particular note is the episode "The Golden Age of Ballooning", where the closing credits ran about halfway through the show.
The next episode, "...
I believe the notorious film Irréversible does this as part of its "reverse chronology" gimmick. The credits roll right at the very beginning, reversed so they scroll from top-to-bottom instead of bottom-to-top.
Even though it doesn't count, as it's not a movie or TV show, I feel obliged to mention Donkey Kong Country. You defeat King K. Rool, a fake set of ...
Yes, he gained weight, did specific exercises, shaved his head, and used make-up artists.
To shape-shift accordingly, Bale has said that he shaved his
head, bleached his eyebrows, and gained 40 pounds. (Co-star Carell
also said that Bale did specific exercises to thicken his neck.) This
January, Bale waved off any praise for the extreme
The 1999 comedy Man on the Moon starts with the main character saying that the film isn't very good and that he has cut out all of the baloney. In fact, he says, this is the end of the movie.
The credits then roll. Then the screen fades to black.
Neon Genesis Evangelion: The End of Evangelion was created as an alternative version of the two last episodes of the TV series, so they put the credits at the middle to presumably emphasize this fact. According to Wikipedia, the episodic version of the film includes two endings, one for each episode, and even a next-episode-preview section in the first one.
In the Garry Marshall comedy Young Doctors in Love (1982), the main character's love interest appears to be dying or dead. The main character is walking away sadly, alone, and the credits start rolling up from the bottom of the screen. The main character looks at the camera and says, "No, not now." The credits reverse direction and scroll back off the ...
Liza, the Fox-Fairy (2015) might be an example. Although the running time after the fake end credits is not substantial (only slightly more than two minutes), it is not an after-credits bonus scene, but part of the movie.
The movie seems to end in a cliffhanger, the frame freezes, and the credits start to roll, with a corresponding music. Then the credits ...
Jan Kounen's 99 francs includes a fake credit sequence in the final quarter of the movie.
The movie features two alternative endings of sorts. After the first ending plays out, the credits start to roll, but after a while, the protagonist interjects and forces the movie to continue, partially undoing some of what was shown before.
This is very much in tone ...
The death of the donor was purely accidental.
Mrs. Cheney statement that "He's not going anywhere" was just an expression of faith in her husband and his recovery and that somehow he would receive a heart.
This should still qualify - there was a Seinfeld episode which was filmed in reverse order so the ending credits actually appeared in the first scene. This doesn't violate what you wrote when you said "The credits should roll during the film, not at the beginning." because this was technically the END of the episode.