XY Leaks

Actually, you have your myths mixed up, the norse myth (that fits with these 3) comes from the tale of the great tree Yggdrasil. At the top, Yveltal, you have a powerful bird, most likely an eagle or a hawk, usually without a name but some legends give it the title Tevalt...on the ground level and on the first branch of this enormous tree is the 4 guardian deer, who represented the 4 main elements (Fire,Wind,Water,Earth) whose antlers were each said to glow the color that corresponds to their element (Xerneas has many antlers, last I counted it was about 8, and the tips of them glow different colors). The 4 of them each had a corresponding name, but as one myth states the grouped name was Hart...finally, you have Zygarde who is based on the snake who lived underground and curled itself around the roots of the tree, and is said to watch and guard the underworld...the name of this escapes me though, but it is a ground-snake. The snake you have it confused with is either the Jormungand, a vicious sea serpent who was said to have fought with Thor in the final battle and was killed while poisoning its enemy..or the mighty leviathan, a powerful sea creature whose true image was never known, some thought it was a serpent, others claimed it was a squid (like the kraken), as well as being a crocodile, a giant whale, a shark, a lobster, and a jellyfish.
Now, according to some of the information we've received from leaks, as well as some slight statements about the region itself, I am almost positive that it does not represent just one of these xyz myths, but in fact all of them, mainly the 3 most talked about: Norse, 3D axis, and DNA. All 3 are seen to have some influence on the games, as you can see that Kalos is based mostly off of Eurasia in some of the images we've seen, it will be the first 3D game of the series, and there are symbols everywhere (mostly with the megas) that resemble that of Double Helix (which is what DNA is said to look like. All 3 ideas have something to do with X, Y, and Z...and if you think about the legendaries, the Norse myth corresponds with the Graphing myth...how? Well, we know X on a graph has to do with the horizontal plane, and since the norse myth details the deer as being on the ground floor, it fits the same theme. Y on a graph deals with the Vertical plane, and the bird in the myth is seen as being up the tree, another fit. Lastly, Z deals with depth, and what else do you think of when you hear that word..either underground or underwater, and the snake lives deep under the tree in the myth, thus we have another perfect fit. As for DNA, I'm not sure how the Legendaries fit in with the idea, but their bodies seem to look as though they were based on veins or something, and the colors match with the Double Helix as well (One side red, the other side blue, and connected in the middle by green)..mostly DNA seems to contribute to the idea of evolution, specifically the megas, and how their own DNA is rapidly changed by certain stones, sort of like how eevee becomes it's several forms.
There's my two cents for ya...I will have to say though, I am pleased with Chesnaught, though I wished it was Grass/Dark that way it would not have a 4x weakness to Delphox...Greninja seemed like it would have been a Water/Fighting, considering it uses the "fighting" techniques of a ninja, but I guess the whole shadowy ninja thing works for it.

I too am waiting on a Dragon/Bug, cause bug types don't get enough love. And what's the deal with there only being one new bug type line in this game, I mean, Vivillian looks pretty cool, but shouldn't there be a Bug/Poison counterpart to it like there has been for almost every gen (4 didn't have twin-like bugs of Flying and Poison, while in 5 Flying was replaced with Grass)? Like: Butterfree & Beedrill, Ledian & Ariados, Beautifly & Dustox, Leavanny & Scolipede. I'm hoping more will be introduced, because this makes a mess of the kind of team I'm attempting to build. I'm also disappointed that there are not alot of new electric or fire types either, makes me feel like it's a repeat of Johto...not to mention quite a few don't seem to evolve or reach a 3rd stage, which makes me wonder how long it will take for certain ones to evolve.