At lvl 72 with flak armor on, a lvl 5 Troodon knocked me out with one attack at night. Last thing I saw was those glowing eyes before passing out. My Guess is that they attack vital organs. Luckily my Doedicarus was up for a game of baseball and launched that little devil out into the stands.
Before you all go naming your griffins "Buckbeak" lemme lay some mythology on ya. Buckbeak from Harry Potter was actually a hippogriff which is a horse combined with a eagle. A griffin is a lion combined with an eagle. Just keep this in mind before going on a Buckbeak naming spree.