Zoroarks secrete a greasy hallucinogen that coats their mane. This toxin can be absorbed through the skin and causes predators and would be prey to see them as a much larger Pokemon than they are. Sometimes their toxin can coagulate into turquoise lumps in their fur, these are known as Zoroark beads and are quite valuable as a recreational hallucinogen. They are notorious for feeding on Natu as they cannot fly yet and Xatu are ground laying birds. Natu's psuchic abilities have no effect on Zorua and Zoroark. Diglett is ready for his closeup.
Nice concept, but it looks more like a werewolf than a fox. Where is the fluffy tail? Don't get me wrong, sifting through your Pokemon artwork I'm in love with your style, but I think some of them aren't entirely close to the description given on where the origins relate to. Not knocking you, don't read this wrong, since I do >really< love your style.