Creature Editing

[Jeansi]

Heyho,

I just want to Know if there is any way to change creature models in live wow(7.0.3), so not a only private server thingy. In particular I want to change the Models for spiders into something else (e.g. Cows, Sheep's, whatever) cause my arachnophobic gf would really love to play but she's freaking out everytime she encounters a spider. So the game is not playable for her. Just facing it is no option, so I had the idea to edit the models for her
After searching the problem I did not find out much...sorry for wall of text here are my questions:

Is this even possible? (Changing looks of enemies Creatures)
If yes, which tools do I need, should I use?

Since I'm new here I hope it's the right section and a legit question. Thanks in advance