Got home, watered, cleaned it up. Added some cinnamon on some squidgy stems.

Not uncommon to see that. Most of these plants are mass propagated by tissue culture these days. I think sometimes the chemicals used in the process produce these aberrations. They're easy to maintain provided you remember they're epiphytes (or lithophytes) and must have very good drainage.

I figured it was a mutation, since most asplenium nidus that I've seen don't look like this. Do you think the mutation will continue further in other leaves? or just stay in what's there already? Interesting about the tissue culture.

I'm well aware of the epiphytic nature. :) Going to repot it in a peat/bark mix this weekend.

I'm only guessing but I expect the odd leaf might turn out like that every now and again. It still looks good and as it gets bigger will look even better.

Thanks!