The product of extreme, brutal Combine engineering, stalkers are humans who have been experimented on by Combine scientists, had their higher brain functions severed, nano-devices embedded into their skin, and their bodies physically altered. HERE A DESCRIPTION OF WHAT AN STALKER IS. I´ve been inspired by the computer game Half Life 2, and by its Art Director Viktor Antonov vision the HL2 atmosphere. T is an speed painting in Photoshop, it took me 45 minutes to do it with an Intuos 3.