Yes, that happened in an end credits scene. The first of the two the movie has. The second one wasn’t important at all. I’m sorry I’ve spoiled it for you. I assumed you had seen it.
I usually sit through the credits if I know the film has an end-credits scene (by the way,
this website I recently discovered is quite useful for knowing that). I agree, though, that sometimes the credits seem to be endless. But my problem, at least some years ago when I saw a Pixar film, for example, was that I was usually the only one staying there during the credits and the theater workers were impatient peeking out from behind the door waiting for me to leave so they could enter and clean the theater before the next showing. So, sometimes I didn’t stay because I felt uncomfortable there. Nowadays though, thanks mainly to superhero films, people are more used to end-credit scenes and there are more people who also stay until the credits have finished. Theater employees have also gotten used to that and they don’t disturb until the movie is completely finished.