I know what you're saying. "There's no dragons in Morrowind!" Not in the actual game, no. But in Skyrim we find a book written by the ancient Dragonguard called Atlas of Dragons. This book was written in 2E 373, more than an era before the wonderful adventures of the Nerevarine take place.
Atlas of Dragons has an interesting bit of information about a certain dragon named Ahbiilok, saying this about the dragon:
Sightings dating back to the early years of the Dragonguard throughout the northern Jerralls. Multiple attempts to kill him have failed. He is believed to be lairing somewhere in Morrowind.
So the book says there is a dragon believed to be hiding in Morrowind. The book doesn't say where in Morrowind, but seeing as Vvardenfell takes up a pretty big chunk of Morrowind, it's possible that Ahbiilok is hiding somewhere on the island.
So why not include him as an Easter egg? Just use a dragon from Skyrim and give it a name. Hide him somewhere to surprise the player, and baby, you've got a stew going! an Easter egg!

That would be nice, although
That would be nice, although I would imagine it would be more likely that Ahbiilok would lair in the Velothi Mountains, there seems to be less Cliff Racers there. Cliff Racer swarms are suprisingly effective against Dovah. Although, there is a chance that he is the supposed dragon found in the "smoking ruins of Vvardendell".
I recall someone making some concept art for him, if he laired in Red Mountain.