Slime WhipWeapon 7
Source Pathfinder Adventure: The Slithering
Damage 1d4 Slashing
Type Martial
Price 360 gp
Weight 1 bulk
This thick, greasy +1 striking shifting whip is made from a slimy pseudopod. You don't take the usual -2 circumstance penalty to your attack rolls when using the slime whip to make a lethal attack. The whip's form can be changed just like any weapon with the shifting rune, but it reverts to its original form as soon as it isn't wielded. When in its whip form, you can use the following action.
Activate 
command, Interact
Frequency once per hour
Effect For 1 round, the slime whip deals acid damage rather than slashing damage. If the attack deals persistent damage, the persistent damage is also acid damage instead of its usual type.
Traits
Something of uncommon rarity requires special training or comes from a particular culture or part of the world. Some character choices give access to uncommon options, and the GM can choose to allow access for anyone. Less is known about uncommon creatures than common creatures. They typically can't be summoned. The DC of Recall Knowledge checks related to these creature is increased by 2.
DisarmYou can use this weapon to Disarm with the Athletics skill even if you don't have a free hand. This uses the weapon's reach (if different from your own) and adds the weapon's item bonus to attack rolls (if any) as an item bonus to the Athletics check. If you critically fail a check to Disarm using the weapon, you can drop the weapon to take the effects of a failure instead of a critical failure. On a critical success, you still need a free hand if you want to take the item.
FinesseYou can use your Dexterity modifier instead of your Strength modifier on attack rolls using this melee weapon. You still use your Strength modifier when calculating damage.
MagicalSomething with the magical trait is imbued with magical energies not tied to a specific tradition of magic. A magical item radiates a magic aura infused with its dominant school of magic. Some items or effects are closely tied to a particular tradition of magic. In these cases, the item has the arcane, divine, occult, or primal trait instead of the magical trait. Any of these traits indicate that the item is magical.
NonlethalAttacks with this weapon are nonlethal, and are used to knock creatures unconscious instead of kill them. You can use a nonlethal weapon to make a lethal attack with a -2 circumstance penalty.
ReachNatural attacks with this trait can be used to attack creatures up to the listed distance away instead of only adjacent creatures. Weapons with this trait are long and can be used to attack creatures up to 10 feet away instead of only adjacent creatures. For creatures that already have reach with the limb or limbs that wield the weapon, the weapon increases their reach by 5 feet.
TransmutationEffects and magic items with this trait are associated with the transmutation school of magic, typically changing something's form.
TripYou can use this weapon to Trip with the Athletics skill even if you don't have a free hand. This uses the weapon's reach (if different from your own) and adds the weapon's item bonus to attack rolls as an item bonus to the Athletics check. If you critically fail a check to Trip using the weapon, you can drop the weapon to take the effects of a failure instead of a critical failure.