We can clearly see the Edward Norton plays Nova in Alita Battle Angel, but his name was not featured in the end credits of the movie.
I checked IMDb as well which didn't show his name. What is the reason for this?
According to this article:
In interviews with director Robert Rodriguez, he revealed that the surprise casting is meant to lock in capable actors for big roles in future Alita sequels, which was a lot tougher to pull off than it looks.
Note that the lack of credit might not solely be due to the surprise effect, but also because of a technicality:
"I tried to find somebody who had a real intelligence to them. We went through a list of people that we could find who were worth bothering to do this, because there's no dialogue or anything. It's really for the setup of, if there was a sequel. We want to put someone here who we would want in a sequel. So it's kind of tough casting to do.