Agreed. If she's got the power to do anything a mythological or fantasy or alien critter can do, then she just has the power to do literally whatever the writer wants, with no limits. That's boring. If she sticks to real world animals there's a slim chance I could actually learn something cool about the world I live in while reading a comic book, and that's part of what I've always loved about comics (and science-fiction) in the first place. If all I wanted was a power fantasy, I could just make that up myself. Ooh, power to resurrect like a phoenix! Power to create tremors like an earthquake beast! Power to grant wishes like the golden fish! Power to fly in space like a space dragon! Boring. Particularly when a writer can just make crap up and claim it's some alien animal, the ultimate in lazy writing.