Magic shape changing armor

[Bub_the_zombie]

I have been searching for rules to create armor that allows you to shape change. All the referance I have been able to find is for wild shaping while wearing armor or lycanthropy and magic armor.

This is what I have in mind, it may explain my search better.

In game we just killed several crocodiles, I delivered the hides to the leather worker / armor smith to create MW croc skin studded leather armor. It is for my dwarf thief/ranger who is an exterminator for the city sewers, he does not swim. Before I wear it I want it enchanted to do the following; shape change into a croc (much like cloak of the manta ray), and have a constant swim speed while not in croc form (even if it is only 5 swim). The look of the armor is quite funny the way it is sketched on paper, think chubby dwarf meets "where the wild things are", meets tacky leather goods.

I have looked through the dmg, and searched online and cannot find how to apply these magic qualities. I remember seeing something like armor of the owl / eagle that let you grow wings to fly for a bit but cannot recall the book or source. Any help would be appreciated with this search.

 

[Sekhmet]

Cloak of the Manta Ray is a great starting point.
It grants a single form for polymorph, plus retains the use of arms.
You want a single form for polymorph, plus a small swim speed bonus when not polymorphed.

I'd set it right about the same price, or about 7500gp.

This is one of those items that would require a DM to make an arbitrary decision based on how effective/awesome he feels the item to be.

 

[RUMBLETiGER]

As [MENTION=97602]Sekhmet[/MENTION] has mentioned, a magic item this specific falls under custom items rules, and are to be worked out with your DM.