Who Is The Arrow Episode 100 Mystery Guest?

Yesterday, Stephen Amell tweeted a photo of himself with a “Mystery Guest” for Episode 100. We already know Jamey Sheridan and Katie Cassidy will be present, but, who else could it be?

Since Arrow Episode 100 is part of a four-show crossover, we’re assuming the “Mystery Guest” is not a series regular on any of the four CW series; otherwise, it might not be a surprise. So who else could be among the possibilities? Here are some thoughts.

Colin Donnell (Tommy)

Once you see where Arrow is going with Season 5, you’ll know that Tommy would be a very relevant, important puzzle piece in the season. Yep, he’s dead, but Marc Guggenheim only said “not Flashpoint” regarding Robert. Maybe he’s Prometheus, even? There are only two things going against this: Colin is currently starring in and quite busy with Chicago Med, his NBC television series. Also, apparently Colin was spotted in Chicago around the time this photo was taken. We can dream though, right?

Susanna Thompson (Moira)

Susanna Thompson has not been on Arrow since Season 2, so her presence would certainly be a surprise. Thompson has recently shot episodes of Timeless in Vancouver, so a pop across town doesn’t seem completely unlikely. With Oliver Queen’s father Robert somehow in the premiere, might his wife be as well?

Colin Salmon (Walter)

Remember Walter? He was pretty awesome. And unlike most of the people on this list, his character is still alive. Now that Limitless is sadly cancelled (boo, CBS), maybe he could come back to Arrow? Please?

Jessica De Gouw (Helena Bertinelli/The Huntress)

We haven’t seen Helena in a LONG time, and her character might be one of the absolute worst people for Oliver to cross paths with at this point in the series. She’s a character who is a major part of Arrow history, though, so it would make sense for her to be brought back up. (Thanks to Forouzan)

Colton Haynes (Roy Harper)

I think we would have heard about it if he was already back in Vancouver, but Roy is one of the most beloved characters and Colton one of the most beloved actors in Arrow. It’d be nice to see him again. Even nicer if it was to set up a Titans show. (Thanks to Hovergrl)

Matt Ryan (John Constantine)

Would they be able to keep his return a surprise? But consider this: There’s a lot of magic in the DCTV universe right now. Supergirl can be defeated by magic. Damien Darhk is back on Legends of Tomorrow. It would make a lot of sense to see him again. (Thanks to Igor)

Manu Bennett (Slade/Deathstroke)

If ever there was an Arrow character people would like to see back, it’s probably Slade. Deathstroke is showing up in the movies soon, which could be problematic, and who knows what Manu’s Shannara schedule is like. Still, an appearance would be welcome, yes?

Celina Jade (Shado)

“Shado” might be dead but hey, so are Robert Queen and Laurel Lance. And we still haven’t seen the Shado that we know from the comics yet. Hmm…

Christie Laing (Carly Diggle)

Did Carly ever find out that Andy was still alive? Will she find out what John Diggle had to do to him? That would make for great drama. Maybe not for Episode 100, though. We’re still putting this down as a possibility, since she’s an important character in the show’s long history.

Kathleen Gati (Raisa the Maid)

The first episode of Arrow featured a maid named Raisa who worked at the Queen residence. She and Oliver got along well. Maybe she was a plant from Anatoly and the Bratva all along? We’re joking, since apparently she knew Oliver before everything happened on the Queen’s Gambit.

Who are we kidding? She’s totally Prometheus. (Thanks to Cory)

Tyler Hoechlin (Superman)

Right now, Superman is only confirmed for the first two episodes of Supergirl Season 2… but the look on Stephen Amell’s face, that’s the look of somebody who’s taking a picture with Superman, right?

Count Vertigo

Whether it’s Werner Zytle or the original version, Count Vertigo could certainly cause Oliver to see dead people. So, we’re putting him on the list.

John Barrowman (Malcolm)

This is a little bit of a cheat, because we know he’s a series regular across all of the series… but certainly he’d be a welcome guest at Arrow any time. Just maybe not a surprising one.

Robbie Amell (Original Recipe Firestorm)

Oh come on, he’s totally not dead. And Stephen always seems happy like this around his cousin. So, we’re throwing this here as a possibility.

Cory Michael Smith (The Riddler)

Lime green. That question mark. We’re finally getting a crossover with Gotham, aren’t we? FIVE SHOW CROSSOVER, BABY! Powerless, you’re next!

The Longshot: Annie Ilonzeh (Joanna)

Once upon a time, Laurel Lance had a best friend. That best friend didn’t come to her funeral, and it would be fascinating to see her response to Laurel’s death and later career as a masked vigilante. Laurel may be gone, but the effects of her legacy would still be really interesting to see here.

What are your thoughts? Leave some comments below!