system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some actors have their name in the credits as "Some Actor as Dr Wilson" and some don't?

i've always been curious about this. Specially when you see the intro-credits to a tv show and its the actors names and suddenly one of them is "THIS ACTOR AS THIS CHARACTER!!". Is there a particular reason?
gpt
It's called "last billing."

The order that the actors are listed in the credits is listed as billing. Generally, the bigger a name you are, the closer to the front you'll be listed. That's called "Top Billing" and it's the best place to be -- listed very first.

But sometimes you'll have two actors of similar stature in the same production. Clearly, both of them can't be listed first, so the next best thing is to be at the end of the credits. Typically, it's separated from the rest of the actors with the word "and" or "with", and sometimes the character name is listed as a way to make the credit stand out more, even though it's not top-billed.

This is the kind of stuff that's worked out with the agents and the lawyers as part of the casting process.