Marshmallows

Marshmallows (マシュマロズ Mashumarozu) are rare Spoon Pets, thus cannot be scooped.

They only appear on the strawberry tart in the Sweets World expansion.

Description
"Fluffy sisters. The younger ones have no chance against the oldest."

Trivia

 * Marshmallows are the one of the few Spoon Pets whose gender is explicitly mentioned in their description.