Arriving a touch late – today’s Ancient Rare is Greater Firebird, the level 46 Carrion Bird who was captured near Abyssal Sands in Tanaris in 2010. It appears the name and model for this Rare has now changed to a two-headed beast called Emberwing.
You can see the previous entry here: Eldinarcus.
Ancient Rares are named mobs who used to be identified by a silver dragon around their portrait. They nearly always drop a tasty item upon death and respawn on long, varied timers. Two Hammers dips into his creaky old collection of screenshots and posts these Rares twice a week. Enjoy the old character models and interface!