Monga

Monga (モンガ) is an unused kaiju originally intended to appear in the 1969 Gamera film, Gamera vs. Guiron.

Gamera vs. Guiron (original draft)
One of the indigenous lifeforms of Terra, Monga would have likely filled a role similar to Space Gyaos' in the final film.

Abilities
Much like Varan, Monga's sole known ability was that it would be able to glide around using the membranes between its limbs.