While fishing in the Dalaran Underbelly, one of the fish that you can get is the [Magic Eater].
One of the items you can be turned into is a green Whelp. While you cannot attack or cast while in this form, and it is not able to be dispelled, you can indeed fish.

In Dalaran, you can find [Underbelly Elixir] around the sewers. The effects are varied but, one of them gives you a buff that says:
“You had always heard that this was “The City of Mages” but this is ridiculous!”
While riding around town, everyone looks like a Human Mage.
It does work while you are mounted and [...]