Supernatural: 10 Best Characters Who Appeared After Season One

Now, this shouldn't come as a surprise to anyone. Without a doubt, the biggest breakout character to have come from Supernatural was everybody's favourite Angel of the Lord: Castiel. Introduced at the beginning of Season Four, Castiel would go on to become the biggest and most popular supporting character on the show. Fans were immediately enamoured with the awkward angel and his fish-out-of-water antics, as well as the man who played him - Mischa Collins.

Originally just a regular angel who simply followed orders, the Winchesters' influence helped him grow a greater sense of agency and identity. This led him to start questioning his fellow angels and to gain a greater appreciation for humanity. It didn't take long for him to become an ally to the boys, but that's not to say the road wasn't rocky. His relationship with the brothers was strained at times, especially when he, you know, went mad with power and declared himself God. But what friendship doesn't have its little issues?

Besides those rough patches though, Cass was a loyal friend who fought by the brothers' side right until the end, when he lost his life (for the hundredth time) in the final season. His final moments were heart-breaking, but a little bittersweet because he had finally felt a moment of pure happiness. In that moment, eleven years of character development were laid bare as we saw just how far he'd come. Equal parts endearing and unintentionally funny, it's clear to see why he was so beloved.