#buffyslays20: Twitter celebrates 20th anniversary of Buffy the Vampire Slayer

Time flies when you're slaying vampires: Friday marks the 20th anniversary of Buffy the Vampire Slayer's debut on The WB, and Buffy fans everywhere — ever present on Twitter — are sharing their joy and appreciation for the groundbreaking teen horror show, using the appropriate hashtag #buffyslays20.

Not to miss out on the moment, Alyson Hannigan (more recently of another beloved show, How I Met Your Mother) had a brief back-and-forth with Buffy creator Joss Whedon, in which she exclaimed, "What can I possibly say to thank you? … I need YOU to write it!"

The Avengers wiz responded in kind, lovingly writing, "And I need you to say it <3":

Read on for some of the funniest, shadiest, and most laudatory #buffyslays20 posts below, and then reflect on the milestone with Angel, a.k.a. David Boreanaz.