In the late 1970s, Mattel licensed toys from various giant robot anime series popular in Japan and released the toys here as Shogun Warriors. The best of the series were a line of 24″ tall plastic that were straight-up awesome, like this classic Dragun:
These toys were released before the U.S. crack down on spring-loaded weapons in toys, so that huge contraption on Dragun’s right hand is a shuriken disc shooter.
The toy line inspired a Shogun Warriors comic book from Marvel that ended once declining sales led to the cancellation of the toys.
There’s a Shogun Warriors fan page that discusses the various lines of toys and variants, while Wikipedia has a nice summary of the toy line’s rise and fall.