One of the Hatchling's name, which is revealed to be Zoe, is first featured here. It was aired on March 17, 2017.
The Blues have to do whatever it takes to extract a whistle from Zoe before she drives them crazy.
Jay, Jake, and Jim were going on for a walk while whistling. Then Zoe, the pink Hatchling friend of them, came along and made a raspberry sound instead of whistling. The Blues were startled by the noise she made and then Jay was laughing at Zoe's failed attempt to whistle. To help her make a whistling sound, Jay tried to show Zoe how to properly whistle, just for her to scream. Jim then gave Zoe a whistle to blow and showed her how to use it. However, instead of blowing as intended, she breathed in the whistle, which somehow allowed her to make a whistling sound., surprising the Blues with the outcome.
Soon however, the Blues were getting irritated by the sound Zoe made so came up with several ways to extract the whistle from her. First, they shook Zoe but the whistle remained lodged in her. Next, Jim tried to scare Zoe to get the whistle out of her but she instead made a starling whistling sound at him. Then, Jim tried to push Zoe off the tree such that when she did a bungee jump, the force would push out the whistle. It did work but the whistle bounced back into her mouth and in the process, also bumped Jim off the tree. Finally, having no choice but to use the final plan, the Blues decided to use a plunger to extract the whistle.
Later on in the Blues' clubhouse, Jim showed what he was going to do to Zoe with the plunger by first demonstrating on a stick pony. However, when the Blues turned their back, she and the pony was gone, just to see her play as a pony rider outside with the stick pony. Miraculously, she tripped and the whistle was outside her. She proceeded to give back the whistle to the Blues, who threw it away in disgust. Just as they breathed in relief, she started hiccuping.
In the credits, Zoe could still be heard hiccuping.