A Marvel Comics superhero will appear with Nathan Fillion on Castle

Here's an curious byproduct of Disney's acquisition of Marvel. We knew that Marvel was publishing a Castle comic book, but on the next season of ABC's mystery comedy, novelist Rick Castle (Fillion) will encounter a Marvel superhero. But who is it?

Said ABC President Paul Lee at a Television Critics Association press conference today:

You know, I don't know if I'm allowed to say it, but we've got a really cool storyline with a Marvel character that appears on Castle this year [...] If you guys haven't seen the finale for Castle from this past season, it's extraordinary. [Castle creator] Andrew Marlow is really hitting his stride. And that was an underrated show that really found its momentum. And there's one episode, and I'm probably giving away a secret and I shouldn't because Andrew is going to kill me, with a Marvel superhero character.

Lee further elaborated that this character would appear during a Halloween episode. A prior Halloween episode of Castle yielded Fillion in "Space Cowboy" gear (above). Could this tie in with ABC's upcoming Marvel-based gumshoe series A.K.A. Jessica Jones? Or will we just see some random perp running around in a Galactus costume?

In any case, I'm putting a totally uninformed sawbuck on the Punisher, as A.) his lack of superpowers jibes with Castle's real-world setting; and B.) he's used to nutty team-ups.

[ IGN via CBM]