The movement: walking quickly and with agility. If you say: how have you mentioned it with different terms: the snake, the jinn, and the serpent? I say: as for the snake, it is a generic name that applies to the male and female, the small and the large. As for the serpent and the jinn, there is a contradiction between them, because the great serpent is among the snakes, and the jinn is slender. In this, there are two views:

One is that at the time of its transformation, it was a snake that turned into a slender yellow snake, then it swelled and its mass increased until it became a serpent. So, the jinn refers to its initial state, and the serpent refers to its final state. The second is that it was in the form of the serpent and the speed of the jinn. The evidence for this is His saying, the Most High: 'So when he saw it moving as if it were a jinn.' And it is said that it had a mane like the mane of a horse. And it is said that there were forty cubits between its jaws.