Can dragons in 4e polymoprh self ? Many stories rely on dragons wlaking unnoticed among the lesser races of Khorvaire. Any official references you can point me out ?
I know I can add this power myslef to the dragons of my campaign. I was just wondering if that was written somewhere.
Thanks for your help.
Wasn't their ability to do this in 3.5e essentially a house-rule from the Eberron books? If the 3.5e Eberron books can introduce the ability for dragons to polymorph as a house rule, I don't see why DMs can't do the same for 4th ed.
There's a silver dragon in the Eberron Campaign Setting named Yllosavax that can change shape. Here is its power:
Change Shape (Minor; encounter) 
Polymorph
Yllosavax alters her physical form to take on the appearance of a young, white-haired female eladrin.
Wasn't their ability to do this in 3.5e essentially a house-rule from the Eberron books? If the 3.5e Eberron books can introduce the ability for dragons to polymorph as a house rule, I don't see why DMs can't do the same for 4th ed.
Some of the metalic dragons have been able to take humanoid shape in the official monster stats in previous editions. The campaign rule (can hardly call it a house rule) in Eberron was a feat-like ability that could be taken by any dragon regardless of species.
Thanks everyone for your feedback, especially for the reference to this silver dragon from the ECG. I guess I'll just add this polymorph power to some dragons, when it's needed for the story. 
I don't even believe it was unique to Eberron, did not Dragonlance dragons have the ability to polymorph into human form as well? I recall silvers were known for doing so constantly.
Bronze, Gold, and Silver dragons all had the Alternate Form ability in 3.5. So that means every dragon of those types could turn into a Medium or smaller animal or humanoid form 3 times per day. Obviously all 3.5 dragons eventually got to pick spells as a sorcerer and could use those for polymorph. So by extension, all Eberron dragons meshed with this backdrop. If this was kept in 4e I have no idea, but that's what the 3.5 srd has to say about it.
Some of the metalic dragons have been able to take humanoid shape in the official monster stats in previous editions. The campaign rule (can hardly call it a house rule) in Eberron was a feat-like ability that could be taken by any dragon regardless of species.
The feat was in Dragons of Eberron, and the point was to say that any dragon had the POTENTIAL to assume a humanoid form, but many never master it. Given the fluid nature of NPCs in 4E (and the suggestions for modifying creatures in DMG2), I think you should feel free to give any Eberron dragon of any color Change Shape if it suits the needs of the story - but again, not EVERY dragon can do it.
Wasn't their ability to do this in 3.5e essentially a house-rule from the Eberron books? If the 3.5e Eberron books can introduce the ability for dragons to polymorph as a house rule, I don't see why DMs can't do the same for 4th ed.
This was a generally common houserule. Gold and Brass (or was it Bronze?) Dragons could assume the shape of a medium humanoid a certain number of times per day. That's it.
People then generally took this to mean that all Dragons could assume pretty much any form they wanted an unlimited number of times per day for as long as they wanted as an innate ability. Even when using the actual Polymorph spell, a Dragon would never be able to maintain the ruse for more than a half hour before having to duck away to recast the spell.
So in reality, there's pretty much no change to how things work. Any Dragon can polymorph into whatever it wants if it suits the situation.
Wayne's World wiggly fingers are your friend. If it suits what you need, have the Dragon polymorph as it sees fit. If the Dragon is merely something malevolent and intimidating in it's size (think angry Red), then don't have them polymorph. Go with what suits you. NPC's are much more fluid in 4e.