Leah wrote:
Not necessarily. That sort of homage gets past copyright law without repercussions, all the time. An excellent example is the Star Trek novel that mentioned quite a few TV Western characters from various series by name.
Not a Paramount-owned TV Western? (No idea)
As a related note: Neil Gaiman, and the Death and Sandman characters. DC Comics does not use them, without Gaiman's prior approval. This is not because he owns the right, but because he'd like creative control. DC own the rights, and may use them as they see fit, but since Gaiman has declared that he'd never work for DC again if they went against these particular wishes, they have an understanding.
Compare also Gaiman's creation of the "Angela" character for McFarlane's Image comics. McFarlane left Marvel and set up his own stable so that he could create a more creator-friendly environment. Didn't stop him reusing Gaiman's character later, and the two writers weren't happy; I don't know whether they've patched things up since.
In other words, who gets say concerning the characters' later use depends on the contract signed at the beginning.
steve