How many poison could produce a poisonous creature each day?

[ayvango]

Poison cost quite a lot. And could be easily obtained with polymorph. Could caster express poison each round while in the polymorphed form?

[Necroticplague]

An indefinite amount, so answer the title question. To answer the question in the actual post:

Milking a single dose of poison from a creature takes 10 minutes of work
Nope, every 10 minutes. He can use the poison as frequently as he can attack with the relevant attack, but extracting it takes 10 minutes.

[Hellpyre]

While a caster could probably produce as much poison as a creature usually could, it may well become inert when the polymorph spell ends. It's probably a better idea to use a creation spell, or alternatively be a shaper Psion.