Who are some of your favorite obscure characters mentioned by name that never actually appear in the show?

A few that capture my imagination are crystal Cassie and her Cassie-role, bake sale enforcer Michael Mauerman, Miss Schnur's talented nephew Nathan and very forward Chinese delivery guy Enrique, and of course, Tony, who's hot but things haven't been going great for a long time

Edit: two more good ones I just thought of: hotshot tanning salon owner/neglectful son Gary Bosco and the late One Eyed Snakes president/meth enthusiast Horny Dave