Polymorphing

[evyldead]

Can you polymorph into a Gloom ?

[Zanos]

Polymorph caps at 15 HD forms.

You could Shapechange into one if you can raise your caster level to 25, however.

[evyldead]

If you do that and you have 10d6 sneak attack do you stack that with the glooms or take the glooms sneak attack ?

[Windstorm]

Polymorph caps at 15 HD forms.

You could Shapechange into one if you can raise your caster level to 25, however.

pretty sure the CL or HD, whichever is lower line still applies to shapechange, the cap is simply increased to 25HD instead of 15, and you're still restricted by your own HD