His best-known character, Wesley Wyndam-Pryce, was first introduced in 1999 to season 3 of "Buffy the Vampire Slayer" as Buffy's replacement Watcher. Originally, Wyndam-Pryce was supposed to be killed off in the season 3 finale but, due to Whedon's surprise at how well he fit into the series, Denisof was given the choice about his character's fate and chose for him to live. As a result, he later showed up in season one, episode 10 of "Angel", and was an official main cast member from episode 11 (effectively replacing Doyle), appearing in 100 out of the 110 episodes of the series. The character was heavily endeared to fans due to the transformation from goofy and lovable, to dark, depressed and moody as a result of events that occur over the course of the series.