I’ve gone down the deeprun tram between stormwind and Iron forge so many times, and I’ve never run down it. I hear its a long run, so I figured why not get off half way near where the tram goes underwater and it looks like an aquarium, I jumped off the tram and couldnt jump up, so i ran further down and found a ramp, and followed the wall back to the glass.. and had a look to take some screenies
So as I was posing against the glass 
When I see a red tagged thing moving around in the water… * Que Jaws theme…….
I mindvision and see a basking shark ! Its a 41 elite
Provided by 
Pugnacious Priest's Warcraft Blog 
There is also a sea monster named Nessy in there. Ive only seen it once as I was passing thru.