Cool - another body still interested!
Had a quick google for gryphons and they all seem to have four legs, so our creature in The Fool is not a gryphon. A similar check on Eagles indicates that an Eagle wouldn't really be an appropriate symbol for holding back our Fool - being associated with all sorts of wonderful myths - being able to look into the eyes of God for a start!
And it's white. Eagles aren't white, certainly not in Europe where the deck was created - any clues as to what else this creature might be?
What creature would represent the kind of thing that holds The Fool back from his wanderings - family, responsibility, tradition, common sense etc?