Shadowed Swarmite

Swarmites are a common sight both in the wilds of Azj-Kahet and among the nerubians who have long domesticated them, but that doesn't make them any less dangerous to incautious adventurers.

Riding Requirements:

This mount is available to all eligible characters on your account.
Level 10
Apprentice Riding (ground)
Expert Riding (flying)

Source:

Achievement: Glory of the Nerub-ar Raider

Notes:

This eerie black swarmite is the meta-achievement reward for the Nerub-ar Palace raid.

Introduced in:

Patch 11.0.2

Travel Mode:

Ground (+60% or +100% speed)
Flying (+150%, +280% or +310% speed)

Speed depends on your riding skill.

Other Mounts Using the Same Model:

Aquamarine Swarmite

Swarmite Skyhunter

Tan Swarmite

More info on Wowhead:

Shadowed Swarmite taught by Reins of the Shadowed Swarmite