If you do not want to build a trap, try and knock it out in a thin canyon area, this way it is likely to get stuck on the canyon walls trying to escape, you will need high health / good armour for this.
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.