Here’s a bit of an interesting analysis: Laura from KimikoGaming.net has written a pretty thorough article about the possibility that the newest cover legendaries for Pokemon X and Y are actually based on Norse mythology. Briefly put, Yveltal (an eagle-esque Pokemon) has features strikingly similar to an mythical eagle that lives atop Yggdrasil (a tree), while Xerneus (a stag-esque Pokemon) looks like the incarnation of all 4 mythical stags. These 4 mythical stags, named Dainn, Dvalinn, Duneyrr, and Durapor, are said to have horns in the shape of Yggdrasil’s branches, with a different colored jewel for each stag. Xerneus, then, has each of the 4 stag’s respective colors on its antlers: Blue (Dainn), Crimson Red (Dvalinn), Yellow (Duneyrr), and Purple (Durapor).

In terms of the axis, Xerneus has no flying capabilities (that we know of), therefore is grounded and representative of the X-Axis (for all of you math illiterates, the X-Axis is the horizontal line), while Yveltal, who obviously have some flying capabilities, is representative of the Y-Axis (the Y-Axis is the vertical line).
Lastly, the article does hint to what the potential and inevitable legendary possibly set for Pokemon Z would be: a dragon. Under the tree of Yggdrasil lies a wyrm/dragon named Niohoggr, Niohoggr has the potential to form a “Z” shape with its body, just as Yveltal and Xerneus had either formed the shape of the letter or had it somewhere on their body, respectively. Also, just as the eagle’s Y-axis goes up and down, and the stag’s X-axis goes left and right, the wyrm’s Z-axis can branch out in all directions.
This is, of course, a rather interesting piece of speculation, but for what it’s worth, everything fits in line with what we know of so far. Nevertheless, we’ll all have a chance to play out the latest chapter in the Pokemon universe, and who knows? Maybe we’ll have a Norse mythology-inspired game with a genetic experimental twist!
Check out the article here!
Update: A follow-up article has been graciously provided by Laura, and covers quite a lot more information, both on her Norse theory and a few other theories! You can check that out here!

Thanks! I think the Pokemon fanbase just grew by 10 fold with all of the cool theories out there so it’s a great subject to write about.
Hello. I actually am the Laura from KimikoGaming. I’m really glad you found my article interesting and decided to post about it. I’m currently doing even more research based on the topic so there may be a follow up article written at some point. Thanks so much for crediting my article and I hope you enjoy the games when they come out!
You did a great job! Keep up the good work, and we’ll be looking forward to your follow-up article!
I posted the follow-up article If you would like to read it: http://www.kimikogaming.net/pokemon-x-and-y-legendary-name-origins-and-possible-future-legendaries/
Thanks again for the post here
Awesome post! Tons of new things that really do make it a great follow-up post!
Thanks, glad you liked it as well ^^