The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
That is an Expy, I would say. There's also Suspiciously Similar Substitute and Captain Ersatz.
Edited by Jerry LOAD"WITTYFORUMSIGNATURE",8,1 FILE NOT FOUND ERRORMight be part of a Pragmatic Adaptation. Novels and films do certain things better, so different personality traits or backstories work better. Screenplays are also often changed according to which actors get cast, so that the character personality and the actor's ability mesh well.

A combination of Canon Immigrant and Adapted Out, when a character has the same role in the story another one did but can't be called the same for whatever reason. Like Petey's butler in Dog Man, who functionally has nothing to do with the butler from the book, but they both fill the same role as Petey's butler.