With her on his back he feels comfortable closing the distance, and then he's practically flying through the air, his body flattening, letting him just get a little more distance.

He gets his mouth on the hulking creature and takes it with him, and thus Marinette, to the forest ground, unable to quite reach the other branches, and several underneath him breaking under his weight. It's his first real ayakashi battle, and he's taken a little aback at his own striking power, though he wasn't as agile as he had thought.

The demon is thrashing about as Snake struggles to keep hold of ayakashi. "Get back, Marinette! He has to wrap around it!" He's not a constrictor type of snake, but it would still take some time for his venom to break down it's defenses, and with it thrashing on the ground, Snake had no choice but to roll with it's movements or let it go. Marinette trying to cling to his tail, even if the fall didn't knock her off, would put her in danger.