Spider Shape (Su): This ability functions as wild shape.
Wild Shape (Su): This ability functions like the alternate form special ability.
Alternate Form (Su): The creature gains the physical ability scores (Str, Dex, Con) of its new form. It retains the mental ability scores (Int, Wis, Cha) of its original form. Apply any changed physical ability score modifiers in all appropriate areas with one exception: the creature retains the hit points of its original form despite any change to its Constitution.
Would the character gain the spider's constitution score for the duration of the spider shape?
Poison (Ex): A monstrous spider has a poisonous bite. The save DCs are Constitution-based.
The Dungeon Master said he may allow Charisma to be used rather than Constitution for the purposes of the poison DC. He is basing his decision on the fact that a Ghoul's disease and paralysis are Charisma based.
But he is also awaiting to see what Stack Exchange comes up with before making that decision.
I am playing this character for fun and flavor. Our campaign consists of:
- Human Necropolitan: Ex-Paladin 4 / Human Paragon 2 / Bone Knight 1
- Human: Rogue 4 / Vampire 1 / Legacy Champion 3
- Half Drow Necropolitan: Drow Template Class 2 / Wizard 5/ Arachnomancer 2
- Frost Giant: Monster Class 9
- Succubus: Monster Class 9
My character (the Arachnomancer): Escaped his slavery of the web pits in the Underdark at venerable years of age (for mental ability increases) and ended up at death's door in a city run by necromancers. For servitude he was "gifted" a second chance as a necropolitan. One of the NPC necromancers was a surface drow as well, and... understood my predicament. He wants to pursue arachnomancy to spite Lolth and use his ancestral knowledge plus gifts of undeath to pursue retribution upon his priestess slavers in the future.
It is an evil campaign. We wanted to have "monsters" as something out of the norm. And I, for once, am not DM'ing this time around.
**Update** 2/7/2015 (8:29 PM +3 GMT)
You have learned to use the necromantic energy that powers your undead form to overcome the inability of undead creatures to wild shape. You can assume the form of an undead, rotten creature with the use of your wild shape ability.
Prerequisite: Undead type, wild shape class feature
Benefit: You can use your wild shape ability even though you are undead. The ability functions just as if you were a living creature using the ability, with the following exceptions. You do not gain a Constitution score in the new form, and you retain all the immunities of the undead type while in your new form. The form you assume looks half-decayed, with missing patches of fur and rotted, worm-eaten flesh. While you are in this form, the rank odor of death hangs around you. Normal
Since it is based on the polymorph spell, wild shape works only on living creatures.
Means the answer would have been "No."