General Mills Makes Marshmallow-Only Lucky Charms Box of Cereal There are only 10 of these "magically delicious" rarities.

 -- Cereal lovers, your wishes for a marshmallow-only box of Lucky Charms have come true.

General Mills announced today the "unicorn of the cereal world" has finally materialized after the Lucky Charms teams received "countless calls, emails, tweets and Facebook posts from marshmallow-obsessed fans."

But there's a catch. Like the pot at the end of the rainbow, these marshmallow-only boxes will be hard to find since there's only 10 of them.

For a chance to win one of the 10, you have to enter General Mills' sweepstakes online by sharing a photo of yourself holding an imaginary box "filled with only the magically-delicious marshmallows" on Facebook, Twitter or Instagram between now and Sunday using the hashtag #Luck10Sweepstakes.

"We wanted to tap into where that love is and it’s across Facebook, Twitter and Instagram," Lucky Charms associate marketing manager Amanda Hill wrote on the blog. "Lucky Charms is one of the most Instagrammed cereals and these platforms are the right place to ignite and connect to the passion we hear about."

She added, "We wanted to have a little fun and connect with our fans. It needed to be easy and accessible for everyone to have a chance to win and celebrate what makes us, us -- the marshmallows."

Hashtag away, marshmallow lovers!