Magical Weapon Property- Shapeshifting?

[DanMcS]

The only thing like this in the DMG is the rod of lordly might, and that's not exactly what I'm after. I have in mind a weapon property that lets the weapon change form, from one melee weapon to another. Anybody seen anything like this published?

If not, what would you rate it? +2 equivalent? What if there was only one alternate form?

 

[UltimaGabe]

I believe there's an ability in the Underdark book that does exactly what you want. I believe it's a +1 ability (called "Shifting"), but as I don't have the book with me, it could be more.

 

[thompgc]

Morphing

UltimaGabe was correct - it is a +1 ability in the Underdark book but the ability is called Morphing.
Morphing enables the weapon to reshape into any other weapon of the same type (light, one handed, two-handed) as a standard action. So cannot morph a dagger into a greatsword.
If morph into a double weapon, only one end is enchanted.

The book also has a +1 ability, Sizing, which lets the size category be changed as a standard action.

The book also has the Everchanging Blade, which is a +1 metalline morphing sizing longsword that can become any +1 weapon the wielder desires.