Let me preface this by coming clean, I have not watched Godzilla vs Kong. In fact, I have not watched any of the movies in the ‘Big Monster Does Big Monster Things’ cinematic universe. All my knowledge of this incredibly fascinating world comes from the 2 minute and 24 second long trailer I watched for the first time 30 minutes ago. All I got from the two minute and 24 second long trailer is that big ape fight big lizard and oh, Millie Bobbie Brown is in this too! Regardless, I am here to offer my completely unsolicited but somewhat scientifically informed opinion on who would win in this titanic tussle, from an ecological physiology point of view of course.

Their size seems like the obvious place to start. Both of our contestants are canonically huge, towering over the skyline of whatever CGI city they’re destroying this time. This alone defys a myriad of biological and chemical limits such as, but not limited to structural support and blood flow.

One of the key reasons why whales can grow that big is that they live in the ocean, where water provides buoyancy to help counteract some of the gravitational forces pulling on the whale’s body. On land, a creature the size of a building would instantly crumble under the weight of its own body, leaving ‘Godzilla vs Kong’ to be more like ‘a puddle of goo vs… another puddle of good (but with bits of fur)’.

Perhaps these monsters have bones made up of some super ultra-hard alien polymer that can withstand the weight of a body that big, you would still need insanely strong muscles and connective tissue that could support the movement of these incredibly heavy structures. If you can sort the muscles out through some other fun sci-fi explanation you still need to supply them with nutrients and oxygen at a quick enough rate to support any movements. A giraffe’s heart needs to work overtime to get blood up to its head, generating a very high blood pressure in the process. To pump blood up to the height Godzilla’s brain is at, not only would its heart have to be stupidly strong, the vessels would have to be durable and wide enough to accommodate the high-pressure flow, while still tapering down to thin capillaries at the end so gasses and nutrients don’t have to diffuse large distances (large distances for gas diffusion is anything more than a millimetre!)

Ok fine, I can suspend my disbelief regarding these very relevant issues to go ahead with this already convoluted discussion, let’s say we now have a very big lizard fighting a very big ape. Who would win?

King Kong would be a typical endotherm, an animal that produces its own internal body heat through metabolism. Its cells essentially act as tiny engines, “burning” sugars through long biochemical pathways to produce heat energy that keeps the body at a constant warm temperature. Godzilla on the other hand would be a typical cold-blooded reptile, an ectotherm who lacks the ability to generate that internal body heat. As the endothermy strategy requires that constant supply of energetic molecules (food) to keep its heat engines running, Kong would be a lot less efficient when it comes to water or oxygen use. As such, Kong would have to spend more time and effort obtaining resources to merely stay alive (time that Godzilla will surely spend plotting Kong’s downfall). At that large of a size, any creature would need massive amounts of food but Kong would have much higher energy demands than Godzilla. As a consequence of the lower metabolic rate, however, Godzilla may choose to have a much more energy-efficient lifestyle: laid back, slow, lethargic, like a crocodile basking in the sun on a river bank. If Kong can find enough food to sustain itself, it would definitely have the upper hand in terms of mobility, strength, and general fighting vigour. 

As things get larger, their volume increases faster than their surface area. This means Kong’s body would be generating a lot more heat but would have a relatively smaller surface to dissipate excess energy out of. Endothermy at such a scale thus comes with the risk of overheating your cells. All that heat energy would also first have to travel a huge distance to the surface of its skin where it would be met with thick insulating hair, blocking its way. This is one of the proposed reasons why we had gigantic ectothermic dinosaurs roaming the earth but no massive endothermic mammals to face them in a war for the planet.

Ultimately, this is but a fun thought experiment, with no real victor to our fictional fight. I’m glad I was able to finally put my coursework to some actual, important, scientifically valuable use. At the very least, I might even go give this movie a watch now. 

After all that if you were to ask me who would win, my money is on the overgrown croc. And there is no intriguing scientific reason behind that, let’s not forget: Godzilla shoots a laser beam out of its mouth.