This paper model is a Big Bertha, a level 3 tower from the video game Total Annihilation, the papercraft was created by TApapercraft. Tt fires highly explosive plasma shells that deal splash damage in a small area, but its most prominent feature is its extremely long range.
The Big Bertha can easily shoot from one base to another over very long distances; however at the cost of very low accuracy and firing rate, plus 1500 energy per shot. For this reason it is most commonly used not as a defensive tower, but as a tactical siege weapon. It has less range than its CORE counterpart, the Intimidator. [Source: wikia]
You can download the papercraft model here: Total Annihilation - Big Bertha Free Paper Model Download