Wild magic is... [Hold on a second, it's weird trying to define something that's so second nature to his worldview.] It's everything that's not relating to one of the nine major covens. There are a lot of smaller covens, but all of their magic can still be sorted into the main covens, like- specialisations.

[He lets Guard crawl up his wrist so he can tick off on his hands.]

A lot of wild animals have magic, or such high natural defences that make confrontation a deadly risk in a best-case scenario. Natural formations like Fool's Blood - the Titan's Veins themselves are impervious to magic, but growths of Fool's Blood means the area is decayed so the entire area becomes a hazard. Witches using the wrong kinds of magic? Learning too much means they set themselves off while they're casting, like dymamite, or it could lash out when they lose control of their emotions.