SPOILER WARNING: This story contains spoilers for the the "Supergirl" Season One finale.


As they did with "Arrow" and "The Flash," the producers of "Supergirl" spent much of the CBS show's first season introducing a number of eclectic and esoteric elements from across the DC Universe. Starting with Vartox in the pilot episode, viewers got to see TV versions of super-people like the Master Jailer, Red Tornado, Martian Manhunter and Maxima. While a second season has yet to be announced formally, odds are good it will include even more familiar characters. A trip to Project Cadmus seems pretty definite, and I wouldn't be surprised to see the Guardian, President Lynda Carter, and/or Streaky the Super-Cat along the way.

And yet, none of those seem to be teased by the final shot of Season One -- which, it must be said, doesn't have much to do with the rest of the episode. If you didn't get the warning up top, this is your last chance to avoid spoilers.

RELATED: "Supergirl" Recap: Kara Says Goodbye to Season One (And Everyone Else)

Season One ends with the arrival of yet another compact Kryptonian spaceship -- yes, like the ones which brought the El cousins to Earth -- landing right in the middle of National City. Supergirl and J'Onn J'Onzz investigate, and the Girl of Steel is shocked to discover whomever (or whatever) the pod is carrying. While we don't see what she does, certainly it seems like the pod's cargo has to be Kryptonian, or at least closely related thereto.

Here, then, are my picks for who -- or what -- might be inside:

AUNT ASTRA



Sure, she got stabbed through the chest with a Kryptonite sword, and received a Kryptonian funeral not long afterward; but many of us can probably think of another Kryptonian who sustained a similarly-fatal-ish injury which didn't quite take. Moreover, Astra's casket could have spent enough time close to Earth's yellow sun that the healing process could have been supercharged. "The Flash" found a way to bring back its Season One villain Harrison Wells -- specifically, by using the actor who played him to play his Earth-2 counterpart -- so I wouldn't be surprised if "Supergirl" did something similar.

ZOR-EL and/or ALURA



Not every set of superhero parents is doomed to a set of early graves. In the Silver Age, unbeknownst to their daughter, Zor-El and Alura ended up in the Phantom Zone-adjacent dimension called (appropriately enough) the "Survival Zone." There they lived until March 1964's "Action Comics" #310, when Supergirl relocated them to the Bottle City of Kandor. Admittedly, considering how the "Supergirl" show has used Alura over the course of Season One, bringing her back in the flesh would be more than a little weird -- not to mention a little Harrison Wells-like -- so Zor-El might be a more likely option. Besides, Zor-El might go better with our next candidate.

THE CYBORG SUPERMAN



As it happens, Zor-El is the most recent Cyborg Superman, "recruited" and transformed by Brainiac to scout around for new worlds to conquer. (Come to think of it, Jeremiah Danvers might also make a good Cyborg Supes candidate. It would even get Dean Cain back in the red-and-blues, sort of.)

Still, as "Flash" and "Arrow" have taught us, characters with familiar civilian names tend to embrace their costumed counterparts before too long. Roy Harper became Arsenal, Laurel Lance (R.I.P.) became Black Canary, and Cisco Ramon is well on the way to Vibe-hood. Using "Hank Henshaw" as the cover identity for the Martian Manhunter was a clever fakeout, but perhaps it just delayed the real Hank's introduction as the Cyborg Superman. In the comics, Hank's transformation was a two-step process involving a shuttle accident and being "uploaded" into the computer systems of baby Kal-El's rocketship. On TV, though, Hank might have been transformed by Krypton's answer to the Swiss Army knife.

THE ERADICATOR



Who says the pod has to contain a person? Introduced in 1989's "Action Comics Annual" #2, the Eradicator was a sort of all-purpose piece of Kryptonian technology.

It restored Superman's powers, repaired his costume, created the Fortress of Solitude, and (lest we forget) tried to terraform Earth in catastrophic ways until Superman got it under control. A few years later during the "Reign of the Supermen" storyline, it impersonated Superman and wound up with its own brief superhero career. Ironically, the Eradicator was the first of Superman's replacements to fall when the Cyborg Supes revealed his master plan. Whether as a device or a person, though, the Eradicator is a useful story generator.

And while we're on the subject of non-humans...

KRYPTO THE SUPER-DOG



Come on -- who doesn't like Krypto? If you thought Supergirl and the Flash were cute together, Supergirl and Krypto would make them look like Darkseid and DeSaad. Even if he only stays for a couple of episodes (because sending him to live with Kal-El is probably easier on the show's budget), it'd be a nice change of pace to start the season with something other than a Big Bad or other show-shattering consequence. Besides, Streaky isn't from Krypton.

LOR-ZOD, AKA CHRIS KENT



Chris Kent debuted some ten years ago, in the first comics collaboration between Richard Donner, Geoff Johns and Adam Kubert (in December 2006's "Action Comics" #844). Born to General Zod and Ursa but raised as the adoptive son of Clark Kent and Lois Lane, eventually he grew into the super-powered Nightwing -- this was during Dick Grayson's Batman career -- and was last seen in the Phantom Zone during 2010's "War of the Supermen" miniseries. We've seen Oliver Queen mentoring junior partners, and it looks like Barry Allen is going to be shepherding a new speedster or two before too long. Regardless, making Supergirl into a mentor would be a new direction for the series, and incidentally would be very close to her original mission of protecting baby Kal-El.

That brings me to the pick I'd personally prefer...

MON-EL



Putting Lar Gand in this particular Kryptonian ship just makes sense. When he landed on Earth in June 1961's "Superboy" #89, the combination of his amnesia and a note from Jor-El led the Boy of Steel to believe that Lar was a long-lost brother. (Superboy named him "Mon-El" because he arrived on a Monday, although it probably wasn't at 8 p.m. Eastern/7 p.m. Central.) Of course, Mon turned out to be a Daxamite, a star-spanning race with powers identical to Kryptonians and a weakness to lead. The latter caused Mon to spend a thousand years in the Phantom Zone, which is probably where a TV-style storyline would end up.

Nevertheless, imagine an extended arc where Kara not only has to mentor a fellow superhero, but it's someone fairly close to her age who's just as powerful; and who won't necessarily heed her advice. With one notable exception, "Supergirl" has stayed away from having Superman or J'Onn J'Onzz rescue its heroine; but a Superboy/Superman stand-in like Mon-El might make that hard to avoid. Of course, the arc would lead inevitably to the Legion, which the show has already teased. Heck, Mon's '90s codename of "M'Onel" comes from the Martian language, so he's got a connection to J'Onn as well.

Thus, after a season of trying to justify Superman's various absences, the time may be right for Mon-El to address the issue head-on. He's got all the Kryptonian powers, a handy "who am I? What is my purpose?" character arc, and a built-in exit strategy. Make it happen, CBS!

Oh, who am I kidding? It'll probably be Alura.

Who do you think is inside? Let us know in the comments!