Godzilla vs. Mothra
Sasori Monster looks much like the Legion (though this monster came before Gamera's Legion) and draws obvious inspiration from scorpions. It has gold-or-yellow spiky body armor, eight eyes (four on its left side, and assuming body symmetry, four on its right side) two claws, and six legs. It also has antennae, pedipalps, and a scorpion stinger.
What role the Sasori Monster would have played is unknown. Other concept art presented alongside the Sasori Monster suggests that it may have been planted onto Godzilla's back and hatched from a mass attached to Godzilla's body, though Sasori Monster's connection to the egg is unconfirmed, as this is just speculation. The Sasori Monster was most likely an early prototype for Gigamoth, a mutant Mothra larva that was replaced by Battra.
The concept art of the Sasori Monster was finished on December 5, 1991.