The Druid gains better claw attacks when shifting as they level up:
Level 5 claw attacks have bonus stats same as a FINE weapon 15% DMG, +4 Accuracy, plus 1 penetration.
Level 9 same as an EXCEPTIONAL weapon 30% DMG, +8 Accuracy, plus 2 penetration.
Level 13 Same as SUPERB weapon 45% DMG, +12 Accuracy, plus 3 penetration.
Haven't played up to level 17 yet but I would assume it continues to scale like other weapons you find in game.
Armor also goes up in accordance with these levels:
(Add plus 2 to each level for Bear form)
Level 1 Armor 8
Level 5 Armor 9
Level 9 Armor 10