The 'Unbeatable?' Pterodactyl: BEATEN.

The 'Unbeatable?' Pterodactyl: BEATEN. is a quest achievement earned for completing the Vigilance on Wings daily quest ten times in Mount Hyjal. The daily quest is accessible after completing the Egg Wave quest.

A letter from Farden Talonshrike
Upon completion, players receive the Chirping Box, attached to a letter from Farden Talonshrike:

Note
This quest rewards whichever companion pet you didn't take when completing the Egg Wave quest.