Hedorah Showa http://tohokingdom.com/kaiju/hedorah_showa.htm#71
Hedorah is scaled up to 120 meters with a mass of 70,000 tons.
Well, this is..........an interesting fight to say the least.
Neither one can punch the other without hurting themself. Hedorah will dry up a little bit if he tries to grapple BG and likewise BG would suffer acid burns that can reduce his arms to nothing but bones if he holds on to long. Hedorah takes hit from hot energy attacks very well so he should be able to take most of the spiral rays until BG reaches 1185+. Hedorah could throw blobs into Goji's eyes and blind him and fly around using sulfuric acid mist and his eye beam will come in handy. His acid makes BG's regen a none factor here. If he grabs Godzilla and flies into the bay then Burning Godzilla is just down right screwed.
On the other hand Burning Godzilla's spiral ray will dry out Hedorah a little bit and it only gets worse as he increases in power with every passing minute. His nuclear pulse will be going off like crazy once he gets close to meltdown and just being near him is dangerous because of his body heat. Once Burning Godzilla gets near 1185+ Hedorah is screwed because his spiral ray is at it's max power and even without regen Godzilla is still almost unkillable.
I'm abstaning right now.
This match could really go either way.
If Hedorah is quick enough he could reduce Burning Godzilla to bones and god forbid Hedorah manages to reach the waters of Tokyo bay. Being able to blind and suffocate him as well as slow BG's regen to a near crawl helps a lot too. On the other hand if Burning Godzilla can endure the fight long enough and keep Hedorah away from the water then eventually all his spiral rays, nuclear pulse, and body temp will dry out Hedorah and kill him.