With Iron Claws
Premise
4e has a slight problem when it comes to natural attacks. There aren't any. Well there are some, but they are kind of shit. If you want to be a master of natural weaponry you are kind of SoL. Until now. Simply take one of the following backgrounds at character creation, and you too can be a master of natural weaponry.
Backgrounds
Raking Claws - Background for Shifter(razorclaw), Shardmind, Gnoll, Thrikreen, Bugbear, Dragonborn: Your race and upbringing have taught you how to use your claws as weapons that are as fierce as any blade. Background Benefit: You gain proficiency with the Raking Claws weapon.
Snapping Fangs - Background for Shifter (longtooth), Shardmind, Goblin, Dragonborn, Vrykola: Your race and upbringing have taught you how to use your teeth in combat to vicious results. Background Benefit: You gain proficiency with the Snapping Fangs weapon.
Powerful Build - Background for Minotaur, Bullywug, Bugbear, Hamadryad, Hobgoblin, Orc, Shardmind, Warforged, Goliath: Your race and upbringing have taught you how to use your muscles in combat to overwhelm and surprise your foes. Background Benefit: You gain proficiency with the Powerful Build weapon.
Weapons
Name Proficiency Damage die keywords Hands Raking Claws +3 1d8 Offhand, Light Blade 1 hand Snapping Fangs +2 1d10 Heavy Blade, Brutal 1 1 hand Powerful Build +2 1d12 Mace, Hammer, Brutal 2 2 hand