Tom Lenk

Appeared in Buffy l'ammazzavampiri (1997) {Real Me (#5.2)} as one of Harmony Kendall's vampire minions. He later had a recurring role as Andrew Wells in the show's sixth and seventh seasons, and Andrew later appeared in two episodes of Angel (1999)'s final season (which, ironically, was the only season in which Harmony actress Mercedes McNab was credited as a series regular).

There's no such thing as a part-time Buffy fan; people watch it compulsively. [at a BtVS convention in Northern Ireland, 30 Sept. 2002]