I liked the Gorn as they were depicted in the old Starfleet Academy game for the PC. It was simple, but pretty effective. A puppet can work not too bad if done good. http://www.youtube.com/watch?v=P7cxpQD1zqY Sounds like Frank Welker did the voice, since I hear Megatron in this.
So...a Muppet? BTW - that's not Welker. Apparently actor Bart McCarthy voiced Zashar. http://www.imdb.com/title/tt0125516/fullcredits#cast