Flashwalker

The flashwalker replaced it's ancestor. Although it is called the flashwalker, not all of them grow flashwalker crystals. Some will grow crystalwalker crystals, which are smoother and less rugged, making it hard for flash forests to survive on it's crystals. However they are plentiful on it's shell-back. The flashwalker evolved to be faster and sleeker than it's ancestor due to predation from the hammertoe and ancestors. Because of this predation, crystalwalkers tended to run into colonies of flash crystalroots, while in these colonies some flash forest spores would get onto their backs and grow in small colonies. When these 'infected' individuals reproduced, the likelihood of their 'children' having some flash forest spores on them was high. This allowed the spread of flash forests far outside their usual habitat.

It is able to secrete a chemical through the nerve cables that grow into whichever crystal inhabits it, inhibitint it's growth to a manageable size. Without this chemical, flashwalker crystals could conceivably grow to heavy to carry. In exchange for this, it shares some of it's nutrients with the crystal. Flashwalker's and their crystalline companions are permanently joined after the initial growing period as the nerve cables eventually bunch together to form a primitive communal brain and nervous system. This means that the bulk of it's brain is outside it's body, under the protective canopy of it's crystalline guest, just like it's ancestors.