Deathmaw

Deathmaw and Worg Pup

Deathmaw is a level 51 aggressive rare wolf that can be found in a few different locations north and south of Dreadmaul Rock in the Burning Steppes. (I have indicated where he can be found in red on the map below.)  He drops the typical green item and a decent amount of experience for toons around his level.

He is also desirable as a hunter pet as he has a unique dark brown coloration and he barks when you click on him. He also matches one of the random Worg Pup colors and the two look really cute out together. The Worg Pup used to be a reward from the quest Kibler's Exotic Pets where you had to go into Lower Blackrock Spire and catch a pup. The pup now drops off of Quartermaster Zigris in Lower Blackrock Spire. 

Deathmaw can be found with NPCScan. You will need to add it, his NPCScan ID is 10077.

You can also use this macro to help find and tame him:
/tar Deathmaw
/stopmacro [noexists]
/cast Tame Beast

Before the Cataclysm his spawn timer was somewhere between 5-8 hours. I am not sure if this is still the case, I had to visit his spawn location at least a couple of times before I found him.