I’ve been going back and watching earlier seasons, which - I thought - had a smaller budget and less recognition. But after taking a closer look at the credits I realized there’s a lot of celebrity heads that are voiced by the actual celebrities. The star trek episode actually had the full original cast - and those weren’t bit parts! I get that the show’s a social commentary, but wouldn’t it have been easier to get sound alikes? Is there a story behind the show’s giant special appearances list?
To add to this, famous actors are media consumers themselves. They may choose to go on a show because they’re fans of the show and/or the cameo sounds like a fun time. Futurama cameos are particularly fascinating, because they allow actors to play themselves in a very surreal context, and if celebrities have a friend who tells them that the behind-the-scenes atmosphere is a lot of fun, that can be enough.
Just as an example, if you’re not aware, Danny DeVito produced, directed, and starred in Matilda pretty much because he wanted to adapt a book his daughters liked.
A fun example is Johnny Depp in Tusk. Dude accepted a nominal fee because he craved the ability to act in goofy, low budget, off-kilter productions again. His agent was mad.
I think another is George Clooney and South Park. Even in its very early days, they were able to get Clooney on to voice a dog for the sole fact that Clooney was a fan of the show.
Didn’t he like help get their movie into production or something? I seem to recall that he was a huge fan, and really used his influence to help them before it became the sensation that it became…
George Clooney and South Park are a good example of this as well.