Below you can see the height difference between the two sets.
These giants have been made in multiple colors including pink, white, green, and silver. I only know of six characters in this set, two less than the smaller scaled lineup. There's five inch knock-offs of Darth Vader, R2-D2, and Chewbacca, plus there's Mutant Crab Man (as I like to call him), the spaceman with toolbox, and the "space hero" shown above. I'll have to give him a name... Mocky Jones? Or is he Mocky's partner, Pinky? I've read people calling him a knock-off of Luke or Han, but I'm just not seeing it.
There's no dates or companies anywhere on the figure.
There's a five piece set on a hanger card that seems to have the Processed Plastic logo on it, so that suggests that these were made by Tim Mee Toys/ Processed Plastic Co. just as their shorter buddies were. The same hanger card says "STAR BATTLE giant size play figures". A comment was left on this page informing me that there were sets packed into a bucket that included small scale figures, a five inch figure (in this case it was Mutant Crab Man), and some X-Wing fighter rockets. I could also imagine these being sold loose, though I've never actually heard that that was ever the case.
This series would make a fine addition to any space collection, plastic mini figure collection, or Star Wars knock-off collection. Mocky Jones proudly stands guard on one of my shelves, patiently awaiting the arrival of Mutant Crab Man and the rest of his crew.