Unicorns don't exist, so before you think this is real, stop right there. Although, if they were real, they would barf colors of the rainbow out. And it would be edible. And that's what Instructable user Danger is my middle name came up with.

Unicorn Barf is a primary colored marshmallow treat that is created by mixing butter with regular sized marshmallows and the marshmallows in kids cereals.
Ever since I found out that you can buy cereal marshmallows in bulk on the internet, I have been dreaming about making cereal marshmallow marshmallow treats. Similar to rice cereal treats, but with only the best part of any cereal- the cereal marshmallows! They have affectionately become known as “unicorn barf” around these parts, for obvious reasons, but what is a bad day for a unicorn is a delicious day for everyone else! They are super simple to make and look really pretty!
Here’s a PDF of the “Unicorn Barf” recipe .