animal AsG

[Lucas]

Are all animals (non weapon wielding creatures) considered AsG 1 in terms of armor?

[Danical]

Get a weapon, swing said wapon at target creature, compare avd of said weapon to charts online.

I would advice using the search function to read up on how GS combat works.

[Latrinsorm]

No. AvD charts and a known weapon are usually the best way to determine which AsG you're facing on any given target. For some weapons and AsGs you might have to go into the DF too; for instance, the broadsword has an AvD of 36 against skin, light leather, and LBP (or possibly torso chain, I can't quite remember).