Then you get the change that makes Hank immediately recognizable as Beast, and it comes out of his own scientific work. While working at Brand Corporation, he uses an experiment…

Then you get the change that makes Hank immediately recognizable as Beast, and it comes out of his own scientific work. While working at Brand Corporation, he uses an experimental formula on himself to disguise his identity and investigate trouble there. He expects to reverse the transformation. That doesn't happen in time. It's an enormous consequence for a decision he thinks he understands. Hank has knowledge, a purpose, and a plan, but he's still working with something dangerous enough to permanently change his appearance. Being the smartest person involved doesn't give him control over every outcome. Afterward, being a mutant becomes much harder to keep private. The original Hank could attract attention because of his build or what he could do. The furry version doesn't have to demonstrate anything. People can make up their minds about him before he opens his mouth. That gives his dialogue a different weight. He's still capable of explaining something precisely, making a joke, or enjoying a conversation, while looking like someone a stranger might be frightened to approach. Those things have to coexist every day. And physically, there's such a specific character on the page now. The fur, the crouching poses, the enormous hands, the way he moves through a room. You can recognize Hank from his posture before you even read his dialogue. The transformation changes how his whole presence works in a scene.