To make
Mawhawk appears you have desecrate a Shrine 500 times, to do that you have to use a
Silencer Extretion on a Shrine.

After u use the
Silencer Extretion the following message with appears.

Keep in mind that when you dessecrate the altar a
Guzzlemaw will spawn near the shrine when you desecrate it.
After do that you have to wait until next Server Save to
Mawhawk appears in his places Here.
There isn't a certain time of the spawn the
Mawhawk can take 5 mins to respawn to 2h, it is completaly random.
And the respawn will be open from the Server Save until the next Server Save.
Sources: UPDATE 10.3, Roshamuul Quest, Mawhawk,