Mecha Birds are similar to the other Non-evolvable pets (Pu pet, Fox pet, Yun Sheng Beast, Alpaca) in the sense they start from level 60 and have no skills. They will also take up a pet slot, have loyalty, and can be ridden. They are obtainable from the Mecha Bird Lucky Box.
Like Moon Wolves, Mecha Birds can "evolve" to become True Mecha Birds and Ultimate Mecha Birds. True Mecha Birds require two level 65 Mecha Birds while Ultimate Mecha Birds require two level 70 True Mecha Birds. The primary difference is in their appearance, where they will get more colors and begin to glow. You will need the True and Ultimate Mecha Bird Alchemy Scrolls from the Item mall to do this, based on their respective kind. Actual Alchemy or High level alchemy is not required for this.