Perhaps this is old news, but I still want to share it to you.. We can build an Elephant Gun from Weapons Depot level 3 : Random Rare Weapon.
It's supposed to be the reward or mastery item from Black Friday Event few months ago.. but now you can have it free (random) from Weapons Depot..
Elephant Gun
Attack 43, Defense 17
Not bad for free items.. but I suggest you to upgrade your Weapons Depot, so you are able to build better weapons.. 
