All of the weapons are purchasable at the traitor store for VIPs.
The Melon Cannon: It's a cannon... that shoots melons. This melon cannon can be deadly when used properly.
The Zombie Infector Rifle: It's a rifle that 'turns' your target into a zombie after 5 seconds.
The Turtle Grenade: It's a grenade that explodes into vicious turtles that will attack anything in their path.
A VIP tag that is visible in the chat so that everybody knows how awesome you are. (If you have admin status you will not receive the tag.)
Finally, access to the votekick command for when admins aren't around. Note, if it is abused you can lose your donator status.