Lower Body Configuration
Not putting this in the article yet as I've not seen an official corroboration, but if you look closely at the Hydra Gundam and Throne Zwei, they each feature hip armor panels that are shaped like an elongated dome. On the Zwei, it's where the Fangs are stored.
Further, if you look at the Gunpla that's been offered, the feet are clearly still Hydra's, just with the foot spikes trimmed down. It's also shown with the legs seemingly folded up and concealed under the cloak.
Taken all together, it's entirely likely the lower body is Hydra's high mobility slide armor, just with the hip plates replaced by Zwei's to give it the fangs. Which would give it eight fangs, of which we saw four. Jadzi (talk) 05:22, March 8, 2018 (UTC)