Daryl is able to avoid the teeth. This wasn't his first rodeo with a canine, after all. He knew how they moved. So when Ghoul lunged forward, Daryl darted to the side, reversing almost immediately as he launched himself toward the pup's back.

That part was instinct. Get his teeth sunk in somewhere soft and let gravity do half the work of pulling him down. In this case, though, he wasn't really out to eviscerate the kid. Just get him to back off and understand this wasn't his territory. So instead of going for the throat (tempting, tempting) he dug his claws into Ghoul's shoulder as his hind legs slid across the pup's back.

If Ghoul thought him being smaller meant he wasn't a threat, he was about to get a lesson in not underestimating an opponent. Daryl's weight belied a strength to match any werewolf's and he put it to good used pulling the pup down on his side.