I love its vague ambiguity. I would rather it be remained in text and not some official imagery to reveal what it truly is. Letting run wild our imaginations with descriptive words of what strange creature it is lurking about. It also in is par with how much encounter the characters have with it as much as we the reading audience do. Being not much. The concept of such a creature is so bizarre. From an evolutionary perspective it could very well be in the making just not now nor in our lifetimes.
Hmm. I don’t think The Future Bird related to the woodpecker. Because they have described its pheromones smell like popcorn. And the only bird of modern day have that’s same smell are the Kakapo. It’s will be funny if the Pacha Kamaq turn out to be the Future Raptor Parrot