This mecha paper model is Banana Guard, Candy People who guard Princess Bubblegum's Castle and Princess Bubblegum, from the American animated television series Adventure Time, the papercraft is created by WebDude.
The Banana Guards always appear in pairs prior to the episode "Princess Cookie," but due to their role in that episode, it's clear that there are a large number of guards that all wear the same banana peel armor. The last known leader of the guards was Root Beer Guy after his predecessor, Captain Banana Guard, was either dismissed or demoted due to incompetence.
The Banana Guards wear armor that has them look like cut bananas with chocolate poured on top, along with some pieces of what appears to be sugar. They are taller than most characters as displayed when they tower over Princess Bubblegum. Their feet are popsicle sticks and they hold long bronze sticks topped with diamond-shaped gems that have similar color to the crystals on their head. While they look like popsicles, they are actually bananas that have popsicle stick legs. Early banana guards resembled plantains. Although most guards are shown to be male, a female Banana Guard is seen in "We Fixed a Truck." [Source: wikia]
You can download the papercraft template here: Adventure Time - Banana Guard Free Papercraft Download