War Drummer

War Drummers are Mag'har orcs located on board the Horde gunship in the Seething Shore.

Trivia

 * They wear alternate Warsong gear.
 * They have no on-click voice.

Speculation
Since they accompany soldiers who fought on Ashran, it is unclear whether they are from the Mag'har faction on Outland or from the ones of alternate Draenor. Despite the battleground's early availability, it's possible they are meant to be the Mag'har allied race representatives, and as such the events on the Seething Shore would lorewise take place after their recruitment into the Horde. Alternatively, they could be Draenor orcs who simply came to Azeroth with the Ashran army in Legion, predating the ones officially recruited in Battle for Azeroth.