The creature is a muscular upright biped, strong enough to easily bend a riffle and even tear down a metallic wall. Its body is covered in scales and has a flat nose like that of a bat, long teeth, and three clawed digits on each hand and plantigrade feet. The Martian is a remarkably resilient creature, seemingly impervious to bullets and able to withstand grenade explosions and electrical discharges strong enough to kill 30 humans. It is however highly vulnerable to the absence of oxygen, and needs to consume huge amounts of the gas when not able to obtain it from predation.