Wanderer's Festival Hatchling

Wanderer's Festival Hatchling is found in Krasarang Wilds during the Wanderer's Festival event, between 9pm to 11pm on Sundays (between 10pm and midnight in Europe). 3-5 will spawn at both the opening and closing ceremonies, and will despawn after around 25 minutes. One hatchling spawns an hour before the ceremony begins, and will continue to spawn until after the closing.

Pet Journal
"Legend has it that a seadragon turtle just like this one grew up to become Shen-zin su, the Wandering Isle. Perhaps your little turtle will grow into something amazing?"