These space whales were something that I stole from an Uncanny X-Men arc in the 80's and used for a Star Wars Roleplaying Campaign in the 90's. Essentially there was an alien race much like the exomorphs from the Aliens(tm) movies but they were a significantly low-technology species.
However, they captured and enslaved these majestic space whales that roam free in space. These particular space whales have the ability to travel through hyperspace naturally. So the aliens (let's call them Brood, because that's what they were in the X-Men), used these Space Whales not only as living star ships, but also as a food source as they consumed them from the inside. So they live inside these space whales, eat the flesh of the space whales, and mount a bunch of gun turrets and other tech on the body of the space whales, complete with that bridge window in the nasal cavity.
Sad, I know. But the X-Men (and also my Star Wars RPG players) managed to free the space whales from the evil Brood.
Drawn in Clip Studio Paint. The timelapse process video is below: