First I must acknowledge the source of inspiration behind my idea:
What's your definition of a shadow port? - Star Wars: Edge of the Empire RPG - FFG Community http://community.fantasyflightgames.com/index.php?/topic/128887-whats-your-definition-of-a-shadow-port/ [From ZTE mobile browser]
After posting a joke, I made a comment about possible bases. One such base was a giant space whale. Though it was a bit of fun, a lightbulb went off in my head and I found myself wondering " why not?"
I like using models, and I found a good toy whale. Would look odd, but imposing on an Armada-scale board.
To find a moving creature with a whole galaxy to migrate across would require the whale was tagged. Only those who shelter there know the frequency to find it. I'll need to think of some food source, so that a droid on the ship can spray it with the scent. Otherwise the ship might have to find an alternative way in.
I'm not entirely sure where the port would be located. Perhaps in the large mouth, or near the blowhole. I imagine a base above an ocean of stomach acid but that might get smelly. Another idea was that it could have lungs, where a base could be, though what it would breath in space I haven't the foggiest.
That is what I have so far.