When Zach first noticed the unknown head about to attack him and the head of Fire, he had a fraction of a second to think that the head would probably hold back in case it hit the head of Fire. It just needed to nip Zach with its wide open maw, after all. It was smart enough to do what the head of Poison wasn't.
However, Zach was wrong. He had underestimated its wit, its brutality, or both.
The unknown head didn't care one lick for the head of Fire. It didn't even try to hide its intentions when attacking Zach with its mouth suddenly closed before it could even reach Zach's hair.
It rammed straight into Zach's barrier. The ground beneath Zach's feet caved in. To the unknown head and Zach, that didn't mean much. It was just a change in footing for one of them, and the target moving back a negligible amount for the other.
But for the ground—the head of Fire—it was devastating.
