I was "doing the analysis" w/ Toy Story not long ago. They basically invented Woody/Buzz out of whole cloth, "guilty of being an incredibly lovable toy by association" (with other incredibly lovable toys). As I'm watching Toy Story with my kid, and seeing classic toys (eg: Mousetrap in the background), all the "friends" are legit copyright classics from other companies, but Buzz and Woody are "Disney/Pixar Exclusives" and nobody else can include them. A clever mechanism that seems to have paid off over two modern generations to guarantee they can "craft" a new copyrighted character at any moment (Buzz 2.0, Space Cowboy 9000, whatever...).