I am playing a druid who has a viper as his animal companion. I'm finding that the DC for the viper's poison (DC 11) makes it less useful as we increase in level. Are there any spells or magical items that can be used to increase the DC of its venom?
Spells that Increase a Venom's Saving Throw DC
There are very few of these. I found no items--magical or otherwise--that increased a creature's venom's save DC.
- The 1st-level Drd spell breath of the jungle [conj] (SpC 39) for 1 min./level at medium range creates a 40-ft.-radius-and-20-ft.-high mist in which poison DCs increase by 2.
- The 2nd-level Sor/Wiz spell increase virulence [trans] (PH2 115) for 1 min./level increases the DC by 2 of a touched creature's poison (or, alternately, of a touched vial of poison).
- The 3rd-level Drd spell Merrshaulk’s kiss [trans] (Dragon #330 71) for 1 min./level grants 1 touched snake/level a +1 morale bonus to attack rolls, a +1 morale bonus to saving throws, a +1 morale a bonus to skill checks, a +2 morale bonus to the save DCs of its poison if venomous, and a +2 morale bonus to grapple checks if it possesses the special ability constrict. Note: Only snakes with the type animal can benefit from this spell.
- The 6th-level Drd spell heighten venom [trans] (Dragon #304 40) for 1 round/level increases by 2 the saving throw DC versus a touched venomous creature's poison; the DC instead increases by 3 at caster level 16 and instead by 4 at caster level 20.
Spells and an Alchemical Item that Penalize a Creature's Saving Throws versus Poison
While not identical to increasing the poison's save DC, reducing a foe's saving throw versus poison is pretty close.
- The 2nd-level Drd spell venomous volley [evoc] (Dragon #330 74) inflicts 1d6/2 levels (Relfex saving throw halves) to creatures in a 15-ft. cone; for 1 min. all creatures in the area suffer a -4 penalty to Fortitude saving throws versus poison. Note: There is no saving throw versus this second effect.
- The 5th-level Drd spell bleed [necro] (CC 117) for 1 round/level causes a touched living creature who fails a Fortitude saving throw, in addition to other effects, to take a -4 penalty on saving throws versus poison.
- The alchemical item poison-friend pod (Dragon #322 34), when it hits a creature or square, creates for 1 round a 10-ft.-radius cloud; creatures "caught in the cloud" make a Fortutide saving throw (DC 15). Failure means the creature takes a -4 penalty to saving throws versus poison for 10 min.
Spells I'd Be Remiss Were I Not to Mention
You'll want these if you're serious about poison.
- The 3rd-level Drd spell venomfire [trans] (SK 158) for 1 hour/level grants 1 venomous creature the ability to deal 1d6 points of acid damage per caster level with its poisonous attacks. Note: Often considered overpowered as the damage is uncapped and allows no saving throw.
- The 5th-level Drd spell empower venom [trans] (Dragon #304 38-9) for 1 round/level increases by half again the ability damage a touched venomous creature's poison inflicts.
- The 7th-level Drd spell maximize venom [trans] (Dragon #304 40) for 1 round/level causes a touched venomous creature's poison to inflict its maximum amount of the ability damage; both initial and secondary damage is affected. Note: The spell has as a material component "a single dose of a particularly dangerous poison... worth at least 700 gp."
The DC for Poison is a formula. The static value listed in a monster's stat block is a convenience so that GMs don't have to calculate it themselves.
From the d20 SRD:
The Fortitude save DC against a creature’s natural poison attack is equal to 10 + ½ poisoning creature’s racial HD + poisoning creature’s Con modifier (the exact DC is given in the creature’s descriptive text).
So if you increase the viper's Con modifier (by spell, feat, item, etc.) the DC for the venom will increase. Off the top of my head Bear's Endurance or an Amulet of Health would both be helpful in increasing the venom's DC.
You can also have the viper take the Ability Focus feat out of the monster manual which ups the DC of a chosen special attack by 2.
Arsenic & Old Lace
For your animal companion, you can consider these options.
- Virulent Poison (Feat, Savage Species) - +2 DC to a natural poison
- Deadly Poison (Feat, Save Species) - Doubles secondary ability damage from natural poison.
- Ability Focus (Poison) (Feat, MM1) - +2 DC for a poisonous attack.
- Venomous Strike (Feat, DotU) - req. 2d6 sneak attack, -1d6 sneak, +2 poison DC
- Poison Expert (Feat, Complete Scoundrel) - +1 DC for one type of poison
Poison Master (Feat, Complete Scoundrel) - +1 ability damage from poisons.
Collar of Venom (Magic Item, BoVD) - Grants an extra poison effect to all natural attacks. Collar of Virulent Venom, expensive, but starts with a DC of 20.
Poison Fangs (Magic Item, Serpent Kingdoms) - Grants a poisonous bite attack, DC scales with level and Con. Cheap.
Breath of the Jungle (Spell, Spell Compendium) - area effect increases poison DCs by 2 in area
- Increase Virulence (Spell, PHBII) - minutes/level increase poison DC by 2
- Toxic Tongue (Spell, Complete Mage) - swift action tongue poison attack
- Venomfire (Spell, Serpent Kingdoms) - Each poisoned attack does an extra amount of damage equal to your CL in d6.
If you are willing to invest some feats and skill points, you can summon powerful vermin and milk them for their poisons, and then increase the resulting DC of the poison yourself. The absolute most powerful poison, however, is of a powerfully poisonous creature with the above feats and spells, milked, with the resulting poison prepared by a creature with the feats that apply to non-natural poisons, and then deployed in an area with the above spells cast.
Note: There is nothing stopping you adding a Collar of Virulent Venom and Poison Fangs to your Viper, thus letting it poison while it poisons and bite while it bites. Or as we in the business like to call it, bite primary attack routine (can full attack), bite secondary attack, both get to poison twice.