Polymorphing dragons

[ajs]

I was reading the bestiary last night and I couldn't find this: dragons can polymorph, but is it just the listed polymorph spell with all its inherent limitations or are they using some innate power I wasn't seeing?

[StabbittyDoom]

Change Shape means "as this spell, but lasts until they choose to change form again and doesn't grant ability mods."

It's in the common rules.

Note that they still have the "you changed size" ability modifiers, just not the modifiers listed by the spell (see the polymorph section).

Normally they only have to specify the form and the spell used for what special qualities they gain, but since dragon specifically says any animal or humanoid one can infer that they mean to bypass the size restrictions change shape normally has.

EDIT: The point of listing the spell is just to say what special qualities you gain of the target creature. The rest is overridden by the Change Shape ability.