By creature do you mean Horcrux? If so, it's because he is a Horcrux. Although, this didn't happen in the book.
Thousands audtioned for the role of Harry Potter.
If you are talking about Daniel Radcliffe yes he did play harry potter in the deathly hallows... :)
From the books, where else?
The elf is called creature. Kreacher actually, but it was Dobby, but he was not stuck in. Everything else is okay.
Someone else you say?Supposing you mean the author of the rest of the series, no.J.K Rowling wrote Harry Potter 7!Answer: No
No, Daniel Radcliffe will resume his role.
Harry Potter books? No. Harry Potter Fanfiction? Heck yes. Fanfiction is basically the fans' way to write stories about HP, and some of them are as long as books.
Harry Potter and the Prisoner of Azkaban is the third book in the original Harry Potter series.
Why? For the same reason that anybody else eats.
J.K. Rowling (author of the Harry Potter series) has stated that she may or may not write more books about Harry Potter or his offspring. Since then, she has not stated anything else.
Everyone's going to die one day. :/
"No one else will die, not for me."