I really have to give credit to my boyfriend for this funny little find, as it was he that stumbled upon Grohl Grohl in his well hidden cave by the beach in the north-western part of Kun Lai Summit in Pandaria. Grohl Grohl is a very much energic hozen, constantly running back and forth playing his drums. According to Wowhead, he has one ability: Alert Drums - Pounds upon the drums of war, calling for reinforcements. Wel, he sure is busy!
It seems likely he is a reference/tribute to Nirvana and Foo Fighters Dave Grohl.
I just love Blizzard!