Metaverse: Matt Smith, Karen Gillan, and Arthur Darvill compare the Doctor to Superman

Is it a bird ... Is it a plane ... No, it's ... a blue police box!

Doctor Who stars Matt Smith (Morbius), Karen Gillan (Gunpowder Milkshake), and Arthur Darvill (DC's Legends of Tomorrow) touched down for a special reunion panel as part of ReedPop's Metaverse with the trio — who played the beloved Eleventh Doctor (Smith) and his two companions Amy Pond and Rory Williams Pond (Gillan and Darvill) — reminiscing about their time in the TARDIS, and the cultural significance of the long-running science fiction series turned global phenomenon.

In fact, early on in the conversation, a comparison was drawn between the Doctor’s cultural relevance and that of another hero with alien origins who arrives on earth to help humankind: Superman.

“[He]’s quintessentially all-American and Doctor Who is quintessentially very British,” said Darvill, considering the comparison between both characters as well as their place in each country’s popular culture.

“It’s part of the fabric of things,” agreed Smith.

Gillan had another series in mind in terms of pop culture similarities.

“My mind went to Saturday Night Live,” said the Guardians of the Galaxy actress. “It’s a really long-running thing that’s a national institution.”

Though she quickly added, “But it has nothing to do with aliens or anything.” 

This isn't the first time Doctor Who and Superman have shared the same space, with former showrunner Steven Moffat (Dracula) actually referencing the character (and his love of the Christopher Reeves movies) in the 2016 Christmas special, "The Return of Doctor Mysterio," which saw a bespectacled male nanny named Grant Gordon masquerade as a superhero with a familiar cowlick called "The Ghost" while working for Lucy, the star reporter he's in love with, and eventually coming to her rescue and saving her.

As it stands, Doctor Who will be back for at least one more season — bringing the season count of the 2005 reboot to 13 — with Jodie Whittaker (Attack the Block) once again donning her coat and scarf as the Thirteenth Doctor. She'll be joined by co-stars Mandip Gill (Yaz), Tosin Cole (Ryan), and Bradley Walsh (Graham).

Doctor Who will be back for a new special called "Revolution of the Daleks." While no date has been set, it's expected to air later this year.