The eyes look just right like in the film. I mean it's a bird so they are going to look a bit dopey always cause they are just so wide eyed and such. Love the amount of teeth this thing has though. I know that Daiei was going to make another monster for Gurion to fight in the movie, but they ran over budget and had to repaint the Gyaos. And honestly....I think I would have preferred the Gyaos over that new monster.
I mean for story purposes it worked a lot better than some new monster on the block. Audiences saw Gyaos go for 3 rounds against Gamera. And nearly twice it killed the turtle. So when you see the space version of it, you are like "omg this bat is going to f'up that stupid looking knife head monster". Two minutes later, and several sliced up pieces of Gyoas; you as the audience are like..."that monster just killed a Gyaos in under a minute. There is no way Gamera can fight him!" I mean yeah Gyaos was just fodder to prove how much stronger Gurion was...but for a story viewpoint it made sense than some monster that the audience is only going to see for 2 minutes before it gets killed.