Marvel's Agents of S.H.I.E.L.D.'s Mid-Season Finale airs tonight, and star Clark Gregg, who plays Agent Coulson, has been dropping teasers via Twitter. One thing that fans have been asking to see on the show is more characters from the Marvel Universe. With many Marvel characters tied up in movie deals or other future TV shows, it's been a big question as to what Marvel characters might have a chance of appearing on the show.

Earlier today, Clark Gregg retweeted a particularly interesting fan comment, along with a tease that the comment might come true. Gregg tweeted, "Maybe we do RT @Jinzo_2400: @SHIELDtv @clarkgregg I’d trust it more if we had at least ONE Marvel character in upcoming shows! #Stingray."

In the original tweet, the Marvel fan specifically mentions Stingray, who isn't exactly one of the most well-known Marvel characters, but who could be a fit for Agents of S.H.I.E.L.D. and tie into Project P.E.G.A.S.U.S, which was mentioned in the Agents of S.H.I.E.L.D. pilot. Stingray is a famed oceanographer named Walter Newell, whose power comes from the Stingray costume he builds.

Of course, it's unclear if Gregg is indicating that maybe fans will see Stingray in specific or just some other Marvel character on an upcoming episode. Marvel's Agents of S.H.I.E.L.D.'s airs on Tuesday nights at 8 PM ET on ABC.