When next to a "normal", they just kinda looked a little different. Someone obviously noticed, and felt like dinkin' with it. Lo and behold, when bred to a normal, more came out looking like it. Then after it was bred with a Mojave to get the Mystic Potion, it was pretty much proven that it was part of the whole "BEL" family.

And any day now, some "Super Mystics" will be hatching.