He is indeed!

Gabriel decided to pay the Winchesters an early visit when he saw how things were playing out for them, and give them a few reminders about how borrowers and sprites constantly have to live.

There is a prequel to Jacob in Wonderland which can be found here, a prompt that I wrote out about the trickster catching wind of them. 

We have considered bringing @neonthebright‘s trickster into the story as well, a fun character named Elias who gets up to quite a few shenanigans in his own storyline! Check out his stories over on her writing blog here!