Alicornutopia

I was using the word as an ability instead of a job description. Looking it up, that is apparently not common usage. I knew the answer to my question-as-worded, and you have answered my question-as-intended.

You may have been thinking of MLP changelings. The ability is usually called "shapeshifter".

I was thinking the word looked like it meant “a thing that can change”.

I really liked this one. How long did it take to write it?

Started it April 16th, according to document age, but I couldn't tell you in hours, I wrote in fits and starts while working concurrently on something else. (Sometimes I just marathon an entire story - Strax took like three hours - and sometimes that just doesn't happen.)