This mecha paper model is Garada K7, the first of the two Mechanical Beasts the Underground Empire unleashed on the World, based on the Mazinger Z (Tranzor Z) manga and anime series, the papercraft is created by AnimeMania.
Garada K7 body was constructed to look like a large menacing skeleton creature. When in combat it uses two large scythes that are connected to the head. For personal combat it swings them madly while long range combat it will detach to damage the enemy.
You can download this robot paper model here: Mazinger Z - Garada K7 Free Mecha Paper Model Download