My Little Pony - Baby Sea Pony - Tiny Bubbles (1984)

One sunny day, Tiny Bubbles was feeling especially adventurous. She decided to play near the old wrecked ship on the bottom of the ocean. To get down that deep, she let some of the air out of her float.

While holding her breath, she spotted a sea urchin. Inside the sea urchin, Tiny Bubbles discovered a rusty old key. When she inserted it into the sea chest, the lid popped open, revealing hundreds of beautiful necklaces, bracelets and glittering gems.

"A buried treasure!" exclaimed Tiny Bubbles. As she spoke, her words were carried up to the surface in air bubbles. All of her baby sea pony friends were delighted when she presented them with treasures from the deep.