This is the second gravity falls/spn thing I've pinned lately. It's like they were made to be crossed over.
34 Amazing Crossovers You Wish Were Real - This Torchwood crossover
I'm so glad I came across this! I just watched Percy Jackson yesterday and was like. Also, for those who didn't catch it, Death (spn) is the Ferryman in Percy Jackson =D<-----wow now I want this crossover.
I've recently discovered the Gravity Falls/Supernatural crossover and it's my favourite thing.