Jor-L is the father of Superman and was a scientist on the planet Krypton discovering the upcoming catastrophe that led to the destruction of it early enough to send his infant son to a different planet.
While his son remains copyrighted for another decade or so, Jor-L the father of Superman is public domain because the first appearances of him and his wife Lora in the 1939 Superman newspaper comic strips did not have proper copyright notice on them at a time that was a requirement.
This also extends to their home planet Krypton.
Notes
You’ll notice I’m not using the later spellings of Jor-El and Lara as those are trademarked as is the term Krypton. But Jor-L is not trademarked.