system
Given the following post, respond as if you're commenting on Reddit:
human
[Kaijus] What criteria must a monster meet to be considered a kaiju?

What criteria must a monster meet to be considered a kaiju? To my knowledge, the requirements of kaijuhood seem so vague and poorly defined that seemingly any giant creature could be considered a kaiju. I have half a mind to call Sharknado, or even the Stay Puft Marshmallow Man, a kaiju. 

If King Kong is a kaiju just because he's a giant gorilla, then shouldn't Clifford the Big Red Dog be a kaiju because he's abnormally large, a different color than normal dogs, and capable of human speech? If being a giant is the baseline requirement of being a kaiju, then Paul Bunyan and his blue ox, the Jolly Green Giant, and maybe even Andre the Giant (since Andre was far larger than an average human) should all be kaijus. 

What about giant, intelligent cosmic beings? Shouldn't they be kaijus? I'm talking about characters like Galactus, Cthulhu, and maybe even Mogo the living planet of the Green Lantern Corps.

Also, you can't tell me that kaijus have to be evil, because Mothra, Gamera, and even King Kong and Godzilla themselves have all performed acts of heroism to protect humanity. 

Sorry for almost writing a full essay here. I'm just genuinely curious (and confused) about this subject.
gpt
If you want to get technical, "kaiju" just means "strange creature" and in Japan can describe various things without respect to size. It's even been used as a convenient term to describe some dinosaurs.