The trace of puttying found around the mouth of the B Type head is said to show the failed attempts to move its mouth.
The A Type head was made of latex to make the mouth movable.
It had a core made of FRP inside and was covered by latex to be more exact.
The “Ultraman Pictorial” has a rare photo that shows A Type Ultraman with its mouth closed. (above left)
It’s quite impressive!
It’s said Ultraman was supposed to spit liquid called Silver Yodo (iodine) from the mouth initially, or I feel like I heard he was supposed to spit fire from the mouth.
But the gimmick to move the mouth caused unnatural wrinkles around the mouth. (According to one explanation, the gimmick itself didn’t work well, either.)
And it was replaced by the B Type head and costume.
But looks like the movable mouth was not easily given up on and the same attempt was made to make the mouth of the full-FRP B Type head movable.
According to Akira Sasaki who sculpted the head, he tried to make the jaw a separate part to make it movable but gave up the idea as that made the surface around the mouth unavoidably uneven.
But looks like another attempt was also made to move the lower lip movable though it was finally omitted.
It’s amazing to find the movable mouth was pursued so eagerly!