Hajime Isayama has inserted here and there in the world of The attack of the Giants, several references to the real world and its myths. If a few chapters ago we made the acquaintance of Marleyans similar to the Romans, while the Eldians are instead identical to the barbarians, in the chapter of July 2020 the mangaka has been made even more of Nordic culture.
In chapter 130 of The Attack of the Giants we saw the march of the colossal giants, followed by Eren Jaeger with a monstrous appearance. The end of the world seems to be near and many references go back to the myth of Ragnarok, popular in Scandinavian mythologies.
Miðgarðsormr is a snake also known as Jormungand, sworn enemy of the thunder god Thor. This has an almost infinite length and with its turns it would be able to completely envelop the Earth. In myth, Miðgarðsormr lives in deep waters and would be a messenger of the arrival of the Ragnarok: the snake will emerge from the waters and contaminate the whole world with its poisonous breath, killing everyone.
One of the first parallels that comes to mind is how both the snake and the colossal giants (with Eren behind) emerge from the waters with unprecedented violence, then starting to kill those on land. The second junction point is in the venomous wind of the snake, this time represented metaphorically by the cloud of hot steam that continuously envelops the colossal giants and that it will burn anyone who is hit by it.
Finally, the coils of the snake will wind around the world and the same is happening with the march, given that, in the last table of The Attack of the Giants 130, with the view at the top you can see the curvature of the Earth and the forces of the giants that are expanding in a circle. This continues the references to Nordic culture, have you found others in previous appointments with the manga?