Okay then, let's rough out some basics.
To begin with, it seems prudent to refer to the 3E version of the bag of devouring
, since that serves as the "feeding orifice" of an Ihagnim:
Bag of Devouring
This bag appears to be an ordinary sack. Detection for magical properties makes it seem as if it were a bag of holding. The sack is, however, a lure used by an extradimensional creature—in fact, one of its feeding orifices.
Any substance of animal or vegetable nature is subject to “swallowing” if thrust within the bag. The bag of devouring is 90% likely to ignore any initial intrusion, but any time thereafter that it senses living flesh within (such as if someone reaches into the bag to pull something out), it is 60% likely to close around the offending member and attempt to draw the whole victim in. The bag has a +8 bonus on grapple checks made to pull someone in.
The bag can hold up to 30 cubic feet of matter. It acts as a bag of holding type I, but each hour it has a 5% cumulative chance of swallowing the contents and then spitting the stuff out in some nonspace or on some other plane. Creatures drawn within are consumed in 1 round. The bag destroys the victim’s body and prevents any form of raising or resurrection that requires part of the corpse. There is a 50% chance that a wish, miracle, or true resurrection spell can restore a devoured victim to life. Check once for each destroyed creature. If the check fails, the creature cannot be brought back to life by mortal magic.
That seems like it'd serve as the basis for some kind of Devouring
special attack. The bag of devouring
uses grapple mechanics to determine whether it's devouring works, so I'm tempted to tweak the monster stats so the starting version has the same +8 grapple modifier as the bag
However, it'll likely be an Ooze or an Aberration, which both have BAB equal to ¾ total Hit Dice, which is +6 for 8 HD. Add +4 for its Large size makes +10, so it'll only have grapple +8 if its Strength modifier were –2.
Strength 6 or 7 seems rather feeble, plus it'd give it a pretty lousy melee attack. Although I guess it could be a melee touch attack to grab its victims, which would.
Large Aberration or Ooze
Hit Dice: 8d#+# (## hp) [8d10 if Ooze, 8d8 if Aberration]
Base Attack/Grapple: +6/+8
Attack: Tentacle +3 melee touch (grapple)
Full Attack: [Two? Four?] tentacles +3 melee touch (grapple)
Space/Reach: 10 ft./ 5 ft. (15 ft. with tentacles)
Special Attacks: Devouring, improved grab
Abilities: Str 6 or 7
Guess we could make it so the extraplanar application of Devouring is considered Medium sized as a bag of devouring
itself is 2 foot by 4 foot, (or just give it a –4 circumstance penalty?). Then if the Ihagnim has Strength 14 or 15 it could have a +12 grapple as a Large ooze, and +8 grapple when devouring
. If the tentacles had a regular melee attack, that'd be:
As Above, Except
Base Attack/Grapple: +6/+12 (+8 when devouring)
Attack: Tentacle +7 melee (grapple)
Full Attack: [Two? Four?] tentacles +7 melee (grapple)
Abilities: Str 14 or 15
A point worth mentioning is a bag of holding type I
has a maximum contents limit of 250 pounds as well as the 30 cubic feet volume limit. That weight is way too low for that volume. 250 lbs is roughly the weight of 4 cubic feet of water, and 30 cubic feet of water would be around 1,875 lbs or just under a ton.
It'd seem better to limit it to a number of creatures of a certain size, as is used for Swallow Whole. Maybe it can devour
1 Medium creature at a time?