Tiffany appeared in the episode The Trials of Michael Kelso where she flirted with Kelso in order for him to makeout with her. It turned out that it was the final test as Kelso refused to makeout with her as he still was in love with Jackie.
Quotes
"Don't you want to have secret makeout fun?"
"Did you believe it? Good, because I take drama."
She is portrayed by Keri Lynn Pratt.