An Evil Creepy Ghidorah...and...His More Violent Nature For The Sequel.

Actually I think creepiness is a part of him due to his origin....

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Space!!!!! BUM BUM BUUUUUUUUM!!!!!

Also no, he shouldnt feed on humans, I feel like it will ruin his character, although he can metaphorically "feed" on fear, death and destruction. 

i dont see how it could ruin him by eating humans. it makes him more menacing in my opinion

While the image looks very creepy and menacing, i dont think it feels Ghidorah-esque enough(Could be from the perspective we are seeing him from i guess). As for him eating people, im not really into that idea. Thats kinda like a lion eating ants, it doesnt feel right.

^ I agree.

I don't really like the idea of a kaiju being "evil". Essentially, Ghidorah's a giant animal.

Well they wouldn't have to show him eating them...i picture it like this:

Godzilla roars from the bay...Ghidorah surprised turns to face him (we can see something in one of his mouths.) excited at the actual size of Godzilla (that and that there is enough meat on him for a lifetime.) Ghidorah spits out what looks like clothes as it hits the ground (ala War of the Gargantuas.) he then flies towards his next meal.

From the more realistic standpoint, feeding on humans makes sense. The only issue is that they are so small compared to him but I don't see a problem with it at all. I wasn't a big fan of the "demonic" picture but I agree that there should be a real sense of fear among characters when he makes an appearance. Lastly, I think that model (bottom picture) is fantastic