Kenner released this Stormtrooper as part of their 12" Large Size figure series. Every Star Wars figure line needs a trooper and things were no different back in 1978 or '79.
Stormtroopers were integral to the Empire's plan for galactic conquest. Their look was iconic and somewhat mysterious as we never really saw them without helmets in the original trilogy. Later they would be defeated by teddy bears with sticks, but in the first Star Wars film, they were deadly (just ask Aunt Beru) and definitely to be feared. Their skull-like appearance made them pretty scary to kids seeing them for the first time. There were even playground debates over whether they were robots or not.
Kenner produced the 12" Stormtrooper in very close fashion to the way they produced the smaller, 3 3/4 inch version. Both versions share almost the same articulation... cut shoulders and cut hips for leg movement. That's it. The 12" trooper also has limited wrist articulation that allows his hands to swivel, slightly. Neither feature any head movement. So, Stormie here has a bit of the Batman film syndrome. In other words, he can't turn his head and must turn his entire torso (or body) to look a different direction.
Despite his lack of articulation, I'm sure kids still had quite a bit of fun with him. I didn't have a large size Stormtrooper as a kid. This guy was purchased at a Comic Convention many years ago. It was the first one I had ever seen and I counted myself very lucky to come across him. Of course, these days, this figure can be found quite readily on Ebay, fairly inexpensively.
The Stormtrooper didn't come with much in the way of accessories, either. He has his blaster rifle and a loop of string at the waist for him to store his gun when he's not turning rebels and old people into scorched piles of bones and bile.
I really love these old Star Wars toys. Back in the days before home videos, toys were the most tangible way for kids to relive the films and having a neat toy like this Stormtrooper went a long way towards feeling like you had a piece of the movie at home with you.