>>38875690People usually confuse Nidhogg with Jormungandr because both are serpent creatures and considering Zygarde is dragon type I can see why you would think it was based on Nidhogg, however once you made the connections with the other forms (all children of Loki and Angborda) and remember Jormungandr is literally the WORLD's serpent it's clear it's based on that one, not Nidhogg