Rusted Proto-Drake

Not as shiny as the other one, but it's still a great find lads. Brann Bronzebeard

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 Ulduar Raider
The Black Market Auction House (rarely)

Notes:

This proto-drake was originally the reward for the 10-player Ulduar meta-achievement, and the Ironbound Proto-Drake was for the 10-player. The achievements have now merged and both mounts are awarded for the one achievement.

Introduced in:

Patch 3.1

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:

Ironbound Proto-Drake

More info on Wowhead:

Rusted Proto-Drake taught by Reins of the Rusted Proto-Drake