When Supernatural bows out after 15 seasons next week, it will end with the honor of being The CW's longest-running series. In fact, Supernatural is so old that when the drama first premiered it actually aired on The WB. That's right: This show is even older than the network it airs on!

After a decade and a half on the air, the core of Supernatural has remained the same: Sam (Jared Padalecki) and Dean Winchester (Jensen Ackles) saving people, hunting things, and continuing the family business — even while that business has expanded to include angels, the Devil (Mark Pellegrino), and even God himself (Rob Benedict). Over the years, the show's cast has also expanded to include beloved mainstays like Misha Collins' Castiel, Mark Sheppard's Crowley, and Alexander Calvert's Jack, as well as fan-favorite recurring guest stars, such as Kim Rhodes' Jody Mills, Felicia Day's Charlie, and Lisa Berry's Billie.

After stopping multiple apocalypses, defeating some of the universe's most formidable foes, and facing down their personal demons (both metaphorical and literal), our Supernatural favorites have been through so much over these 15 years. So in honor of Supernatural's upcoming series finale, we decided to look back at how far the stars have come from their first appearances to now.

Celebrate the Supernatural Series Finale With Winchester Week

Get nostalgic with us by checking out the gallery below to see how the cast of Supernatural has changed over the show's many, many seasons — including then-and-now pics of Ackles, Padalecki, Collins, Jeffrey Dean Morgan (John), Jim Beaver (Bobby), Katie Cassidy (Ruby), and so many more!