Sometimes when they adapt a book or a story or a play, the Powers That Be in charge of it decide that the name’s just WRONG. It’s too long, or it sounds too silly, or it has Bad or Inappropriate Associations. So they change it.
1,) Too long – In John Farris’ novel The Fury the Bad Guy is named Childermass. For the movie they shortened it to Childress.
2.) Too silly-sounding. – James Fenimore Cooper introduced the character of Natty Bumppo in his novel The Pioneers, where we see him as an old, somewhat comic guy. When he later wrote about him in his youth, where he’s an Action Hero and a Crack Shot, he usually avoided the name and called him by one of his nicknames – Hawkeye or Deerslayer or Leatherstocking. But that’s not what I’m pointing out here. When Daniel Day-Lewis plated him the 1992 version of Last of the Mohicans they cleaned up Natty Bumppo to Nathaniel Poe
3.) Too Political – in the Philip K. Dick short story We Can Remember it for You Wholesale the lead character is Douglas Quail. When Paul Verhoeven cast Arnold Schwartzenegger in the part in Total Recall, Dan Quayle was the Vice President, so they changed the name to Douglas Quaid. When they remade Total Recall in 2012, Quayle was long out of office, and they could’ve gone back to Quail, but they kept the same name.
4.) Too unpronounceable – In Douglas Preston and Lincoln Child’s first thriller, Relic, the monster known to the Kothoga tribe in South America is called the Mbwun. When they turned it into the 1997 film, they must’ve figured that nobody likes a name that starts with three consonants that are never together in English, so they appropriated the tribe’s name for the monster and called it the Kothoga. (As I recall, they simply never named the tribe)
5.) Sounds incorrect – In Harry Bates’ science fiction story Farewell to the Master the giant robot is named Gnut, which sounds kinda Scandinavian. For the movie The Day the Earth Stood Still, he became Gort, giving us the classic line “Gort, Klaatu Barada Nikto”. True to form, when they remade the film in 2008, they kept the name Gort.
I know that there are plenty of other cases where they changed the names for the movie or TV show, sometimes for No Apparent Reason. Whaddaya got?