Most Elseworlds can be described as "A familiar character (usually either Batman or Superman) IN SOME OTHER TIME PERIOD! This dates back to the proto-Elseworld, Gotham by Gaslight, set in the 1890s; other examples include Kal (Middle Ages), The Batman of Arkham (1900), and Shogun of Steel (Feudal era Japan).
There's a comic book adaptation of Moby-Dick in space. The whalers are asteroid miners, the giant squid is a white star named Kraken, Moby Dick is a (possibly sentient?) comet, and the final harpoon is a 10-megaton warhead.
Ramayan 3392 AD is the Ramayama IN THE POSTAPOCALYPTIC FUTURE!
Marvel's Space: Punisher miniseries is almost Exactly What It Says on the Tin — The PunisherIN SPACE! (The inexplicable colon in the title seems to suggest Marvel is slightly embarrassed to look like they're embracing this trope that blatantly.)
Marvel'sWhat If? v1 #14 featured a story called "What If Sgt Fury Fought WWII in Outer Space?", although this was a reimagining of the same events depicted in mainstream Marvel rather than a spinoff or sequel.