Tohl Narita: “The idea originated from a fish and bat.”
I find Alien Icarus is another attractive alien in its design and sculpture along with his particular behaviors performed in the show.
The unexpectedness of the alien who looks more like a beast than an intelligent life form might be another attractive feature of this alien while he doesn’t look like a kaiju at any rate.
It is well known that his hair was made of brushes from scrubbing brushes, and Tetsuo Yamamura says in a book that he saw the staff make it darker on the set with a spray as it was brighter originally.
And he adds he saw the staff of the Tsuburaya Sculpting Section rub the costume surface with sponges to add weathering to the suit as it looked too clean and smooth when the costume was delivered to the studio.
While you can see his ears move or wiggle like flapping wings, they were moved manually by one of the crew from behind, and it is known that his hands were accidentally shown for a moment in the scene (you can find it out in stop motion).
I think the alien’s side view is pretty attractive in its shape that is distinctive from kaijus. As it seems that there were not always side views and back views of characters drawn by Narita in his designs, Ryosaku Takayama might have sculpted the costume into that shape at his discretion.
As the illustration of Alien Icarus is described as it was drawn in 1983, it might have been drawn by Narita to make it appear in one of his art books published in the same year while I like the ink drawing with pen strokes typical of Narita so much that it makes me feel like drawing pen and ink pictures like that.