[Quitti]

Snake ring: pr100 and gives the commander ability (no matter about the magic skill) to cast spell "poison touch" which is a normal len0 attack that (not very surprisingly) does poison damage. Not sure about how much though. It does not add any attacks nor it doesn't add poison damage to any existing attacks, and it doesn't stack with quickness being a spell.

You can check the spell itself, it's alteration level 1 spell, and requires an attack roll from the caster to hit.

Similar items are sceptre of authority (flame bolt), Herald Lance (solar rays), Skull standard (panic), Skullface (raise skeletons) and many others.