Maybe it's the pain in his leg, or maybe there's poison on the arrow head and it's making him delirious but at that comment about morphing into sonic, Peter just starts laughing. It's not even that funny of a joke but he can't help it-for some reason it just really hit him funny.

That is, he's laughing all the way up until that knife goes into his leg, then he lets out a sharp yelp and tries to jerk back and yelps again because that sure didn't help anything.

"Holy Shit." He takes in a breath. "I-I'm good. I'm-" He needs to calm down before he has a panic attack. He glances down to see where there's blood oozing out of his leg. His face places. That was a bad idea. Such a bad idea.

Focus on something else.

"H-hey can-can I tell you a bad chemistry joke? I'd-I'd tell you a good one but they Argon."