This paper model is Fionna's Crystal Sword, a weapon from the American animated television series Adventure Time, the paper model was created by aiko-chan14. It was given to her by the Ice Queen disguised as Prince Gumball. The sword has the appearance of a ruby, and it has a pinkish glow.
The sword is also retractable, akin to a lightsaber. At the Ice Queen's command though, the sword turns into a giant block of ice, encasing the wielder's hands. Fionna proved that this too was an adequate weapon by using the ice block to beat Ice Queen over the head and shatter the icicle encasing Prince Gumball.
You can download these paper craft toys here: Adventure Time - Fionna's Crystal Sword Free Papercraft Download