Gigamoth

#Gigamoth is an unused Toho Kaiju. Here's a small bit of backstory from Toho Kingdom.

Created as a sort of blueprint for what would end up being Battra in Godzilla vs. Mothra (1992), Gigamoth was perceived as a dark, pollution spawned, twin of Mothra. The creature shares some resemblance to Yoshimitsu Banno's Hedorah, from his 1971 film Godzilla vs. Hedorah. While not having any appearance link, the creature does have similar powers with acidic mist and his immunity to Godzilla's ray and his pollution inspired origin.

Quite a bit of concept art for the creature was created before the project as a whole was eventually scrapped. A lot of this concept art was then rolled over and reconsidered for Battra.