There are some puppet monsters with no actor inside besides the suit monsters in “Ultra Seven.”
It seems to be because it’s cost efficient.
Alien Cool, Alien Vira, Alien Chibull and Alien Poll which I mentioned before are all puppet monsters (aliens).
But it is also true the puppet monsters were unique in the shape as no actor is supposed to get in.
I remember Tohl Narita also said something to the effect that he likes designing puppet monsters because he can design them more free-mindedly than suit monsters.
But, as a child looking forward to the battles between Seven and the monsters at the time, I found the puppet monsters a bit unsatisfactory to be honest.
Because an exciting bout couldn’t be expected from the puppet monsters with limited motion.
Space Dragon Nurse (Shouldn’t it be spelled as Narse?) appearing in Episode 11 “Fly to Devil’s Mountain” is also a puppet.
Though it looks like a robot, it’s explained just as “Space Dragon” in the setting.
The abstract and futuristic head design is exactly the work expected from Tohl Narita.
Gumonga (Episode 18: Escape from Area X) is a pawn monster controlled under Alien Bell (suit monster).
Gumonga attacks humans by putting out poisonous gas.
Alien Bell unexpectedly fights bravely with Seven.