Which character only appeared in one episode, that you wished stayed for more episodes?

So I’m rewatching the show atm and recently watched season 4 episode 1. we only got to see very little of Zack but he immediately seemed like an interesting and funny character that I would have loved to see more of. Could have given us some funny scenes with him and Daryl and also would have been interesting to see how different Beth’s story would have been, had Zack not died.

So if you had to pick one character who only appeared for one episode, who would it be?