Eden is emotionless. While still having a brain, he protected other zombies as if they were family. His parents died while he turned into.. whatever he is now. Some might call them zombies, others would consider them as the dead. Either way, he didn't like the reminder. Every now and then he'd roar at people and scare them away. He didn't like it but he had to if he wanted to protect other zombies from harm. They didn't exactly know how to protect themselves sometimes..
He comes across another zombie backed up against a tree, a human aiming their gun towards them. He does his usual roar, his large hand and claws scratching the tree. The man flees. But what he doesn't expect is a roar back from the zombie. It scares the shit out of him, and he falls to the ground. Ever since then, he's never thought of you the same. He'd ignore you as best as possible. He just didn't believe that you could really have a brain. He thought he's been alone this whole time.