Eidolon and poison attacks

[Cav5150]

Can my Eidolon make two poison attacks per round?
It has two heads each with bite and a poison attack.

The rule states it can only be used 1/round...but is that per separate bite attack?

Poison (Ex)

An eidolon secretes toxic venom, gaining a poison attack. Pick one bite or sting attack. Whenever the selected attack hits, the target is poisoned.

Eidolon poison—type poison (injury); save Fort negates; frequency 1/round for 4 rounds; effect 1d4 Str damage; cure 1 save.

The save DC is equal to 10 + 1/2 the eidolon’s HD + the eidolon’s Constitution modifier.

For 2 additional evolution points, this poison deals Constitution damage instead. This poison can be used no more than once per round. The summoner must be at least 7th level before selecting this evolution. Source: Advanced Player's Guide

[Malfus]

It's 1/round.
emphasis mine.

[Corodix]

The real question is what "This poison" refers to. Does it refer to all the Poison evolutions you have, or just to one of them?

I think you can actually use it twice per round.

Example, three bite attacks, A, B and C. The Poison evolution states that you have to pick one attack, so you need to take this evolution three times if you want to apply it to all bite attacks.

Bite attack A has been upgraded with Poison, 4 evolution points version (so con damage).
Bite attack B has been upgraded with Poison, 2 evolution points version (so str damage).
Bite attack C has been upgraded with Poison, 4 evolution points version (so con damage).
Total evolution points spend on the Poison attacks (ignoring head/bite costs): 10

These are clearly different poisons from different glands (sources), so if we assume that "This poison" from "This poison can be used no more than once per round" applies seperatly to each poison then each bite attack can deliver it's poison attack once per round, resulting in three poison attacks in one round if they all hit.

If on the other hand "This poison" refers to all the poison evolutions that you have, then you can only use it once per round AND all three would deal Con instead of two doing Con and one doing Str damage because: "For 2 additional evolution points, this poison deals Constitution damage instead". The "This Poison" in that sentence clearly refers to the same thing as "This Poison" in the sentence that talks about the once per round thing.
This interpretation would mean that the following is actually the case:

Bite attack A has been upgraded with Poison, 4 evolution points version (so con damage).
Bite attack B has been upgraded with Poison, 2 evolution points version (so con damage since 2 extra points were spend on the Poison of A to give Con damage to all Poison evolutions).
Bite attack C has been upgraded with Poison, 2 evolution points version (so so con damage since 2 extra points were spend on the Poison of A to give Con damage to all Poison evolutions).
Total evolution points spend on the Poison attacks (ignoring head/bite costs): 8

Now Interpretation 2 seems completely illogical to me, I believe that "This Poison" refers to one individual Poison evolution and not to all the evolutions you have due to the way it's also used in the sentence about upgrading it to Con damage. The limit of "This poison can be used no more than once per round" means that you cannot deliver the same Poison attack twice in one round, which could normally for example be done if you have 1-2 natural attacks and the Multiattack feat to get an extra attack with one of your natural weapons. That way you could make two attacks with the weapon that has Poison.
But two different natural weapons with two seperate Poison evolutions should both be able to hit and deliver their poisons in the same round.

So I'd say 1/round for each bite attack, making it 2/round total for you. If both poisons deal the same kind of damage then they are the same poison in this case for dealing with the way poisons work (so no dealing 2d4 con damage in one round, the second hit would instead increase duration and DC).

Now I could be interpreting it totally incorrectly here, but the 1/round even if you have more Poison attacks just doesn't make sense to me when also taking the usage of "This Poison" into account in: "For 2 additional evolution points, this poison deals Constitution damage instead."

Edit: I did just notice that the evolution doesn't state that you can take it more than once, while most others specifically state it when you can take them more than once. So if you can only take the Poison evolution once then you can indeed only use it once per round and only one bite attack can possibly deliver it, never both.

[Malfus]

Corodix wrote:

The real question is what "This poison" refers to. Does it refer to all the Poison evolutions you have, or just to one of them?

I think you can actually use it twice per round.

Example, three bite attacks, A, B and C. The Poison evolution states that you have to pick one attack, so you need to take this evolution three times if you want to apply it to all bite attacks.

Bite attack A has been upgraded with Poison, 4 evolution points version (so con damage).
Bite attack B has been upgraded with Poison, 2 evolution points version (so str damage).
Bite attack C has been upgraded with Poison, 4 evolution points version (so con damage).
Total evolution points spend on the Poison attacks (ignoring head/bite costs): 10

These are clearly different poisons from different glands (sources), so if we assume that "This poison" from "This poison can be used no more than once per round" applies seperatly to each poison then each bite attack can deliver it's poison attack once per round, resulting in three poison attacks in one round if they all hit.

If on the other hand "This poison" refers to all the poison evolutions that you have, then you can only use it once per round AND all three would deal Con instead of two doing Con and one doing Str damage because: "For 2 additional evolution points, this poison deals Constitution damage instead". The "This Poison" in that sentence clearly refers to the same thing as "This Poison" in the sentence that talks about the once per round thing.
This interpretation would mean that the following is actually the case:

Bite attack A has been upgraded with Poison, 4 evolution points version (so con damage).
Bite attack B has been upgraded with Poison, 2 evolution points version (so con damage since 2 extra points were spend on the Poison of A to give Con damage to all Poison evolutions).
Bite attack C has been upgraded with Poison, 2 evolution points version (so so con damage since 2 extra points were spend on the Poison of A to give Con damage to all Poison evolutions)....

One problem, the evolution doesn't say you can take it multiple times. There are stipulations that allow for other evolutions to be taken multiple times, not so with poison. You only get one (unless your GM lets you of course ;))

[Archaeik]

Quote:

Can my Eidolon make two poison attacks per round?

It has two heads each with bite and a poison attack.

The rule states it can only be used 1/round...but is that per separate bite attack?

Poison (Ex)

An eidolon secretes toxic venom, gaining a poison attack. Pick one bite or sting attack. Whenever the selected attack hits, the target is poisoned.

Eidolon poison—type poison (injury); save Fort negates; frequency 1/round for 4 rounds; effect 1d4 Str damage; cure 1 save.

The save DC is equal to 10 + 1/2 the eidolon’s HD + the eidolon’s Constitution modifier.

For 2 additional evolution points, this poison deals Constitution damage instead. This poison can be used no more than once per round. The summoner must be at least 7th level before selecting this evolution. Source: Advanced Player's Guide

Combined with not being able to take it more than once(which is typical) means you don't get to use this trick.

However, it is possible to find ways to hit multiple times with poisoned attacks(just not this one).
This should be the relevant rule. The example should be good enough to figure it out.

http://www.d20pfsrd.com/gamemastering/afflictions/poison

Quote:

Unlike other afflictions, multiple doses of the same poison stack (see FAQ for additional information.) Poisons delivered by injury and contact cannot inflict more than one dose of poison at a time, but inhaled and ingested poisons can inflict multiple doses at once. Each additional dose extends the total duration of the poison (as noted under frequency) by half its total duration. In addition, each dose of poison increases the DC to resist the poison by +2. This increase is cumulative. Multiple doses do not alter the cure conditions of the poison, and meeting these conditions ends the affliction for all the doses. For example, a character is bit three times in the same round by a trio of Medium monstrous spiders, injecting him with three doses of Medium spider venom. The unfortunate character must make a DC 18 Fortitude save for the next 8 rounds. Fortunately, just one successful save cures the character of all three doses of the poison.

And to comment on the OPs creature.

If you do have 2 poison evos, I'd say each is usable once per round, but as the rules preclude the possibility of having 2 poison attacks, well... it's easy to argue otherwise(since they might be considered the same attack). But, it would only increase the DC/duration as above.