Angus McIntyre on Nostr: (puts on Tolkien pedant hat) “Wormtongue” was a nickname or epithet that he ...

(puts on Tolkien pedant hat) “Wormtongue” was a nickname or epithet that he earned by his behavior; Gandalf calls him “Grima, son of Galmód”, so that was presumably how he was known among his peers before he started acting as a lobbyist for Saruman.

It’s more like calling someone, say, Kegbreath or Couchfucker than a family name like Starkiller. Although, who knows? Maybe in Lucas’s universe star-killing is a basic trade that became a family name like Baker or Miller.