In "For The Girl Who Has Everything," the 13th episode of "Supergirl's" premiere season, Krypton was never destroyed -- or, at least, that's what Kara believes after she's attacked by a parasitic alien. Kara imagines a world where Krypton survived, which means her family -- including her younger cousin, Kal-El -- are together once more. Daniel DiMaggio has been cast to play Kal-El, who never grew up to be Superman in this reality.
According to the official episode description, "Kara's friends must find a way to save her life when a parasitic alien attaches itself to her and traps her in a dream world where her family is alive and her home planet was never destroyed. Also, Alex, Hank and the DEO must fend off a Kryptonian attack while Kara is out of commission."
DiMaggio has appeared in a handful of smaller roles, including "Tales of Halloween," "Clarence" and "Burn Notice."
"Supergirl" airs Mondays at 8 pm EST on CBS. Developed by producers Greg Berlanti, Ali Adler and Andrew Kreisberg, the series stars Melissa Benoist, Calista Flockhart, David Harewood and Chyler Leigh.