Next time - ideas our campaign

 Maybe have this Entrope creature. They eat away at reality between planes, and allow stuff to spill over. 

https://www.completecompendium.com/appendix/entrope/

NOTE: 

High HPs (for 2e). Maybe I give them max, so 11 HD + 6 would be 88 plus 6, 94 HP. 

Special Defenses: Info:

Struck only by +2 or better weapons, immune to elements The Doomguard - ever interested in entropy - decided to make sure that it is true and to help the process along. Hence, their magicians and alchemists began devising a means to dissolve the barriers between the Elemental Planes. Hundreds of years of research, trials, and errors took place, but eventually they succeeded. They constructed magical creatures the Sinkers named entropes. Entropes feed on whatever makes up the borders separating the various Inner Planes. As they feed, the elements of the two planes blend and “bubbles” of foreign elements are introduced into alien planes. Eventually, the Doomguard hopes, the barriers will weaken enough so that the planes constantly bleed into each other, eventually becoming indistinguishable. The first batch of these beasts escaped Doomguard control and now wander about the Inner Planes on their own, chewing away at the fabric of reality wherever they see fit. The second group is more closely controlled. Special Defenses: Combat: Because the entrope can literally break down the fabric of reality, it's nothing to fool around with. Anywhere within the Inner Planes, the beast can “eat” through elermental borders, creating a small, temporary hole in space leading to any other Inner Plane. The rent results in a mass of the foreign element bursting into the plane with great power. While the entrope itself isn't harmed by this action, anyone within 25 feet is subject to the elemental explosion. The results depend on which plane the hole leads to (a decision made by the entrope): Air, Earth, Mineral, Ooze, Salt, Water: Matter or air explodes through the hole with great force, inflicting 3d10 points of impact damage (save versus breath weapon for half). Victims must save versus breath weapon or be knocked down and/or back 10 feet; they're also stunned for 1 round afterward. Ash, Dust, Smoke, Steam: Particulate matter bursts through the tear, inflicting 2d6 points of impact damage (save versus breath weapons for half). What's more, all victims must save versus poison or cough and choke for 1d6 rounds, incapacitated. Fire, Lightning, Positive Energy, Radiance: Raw energy gushes through the rent, inflicting 8d6 points of damage (save versus breath weapon for half). Ice, Magma: Energy (along with varying amounts of matter) erupts through the tear, inflicting 6d6 points of heat or cold damage (save versus breath weapon for half). Victims must save versus breath weapon or be knocked down and/or back 10 feet. Negative Energy: This hole sucks the life energy from all victims, draining one experience level from each. Vacuum: Matter and energy is drawn into this rent. The implosion inflicts 3d6 points of damage (save versus breath weapon for half) on victims and requires them to make a save versus death magic to avoid being pulled into the plane of Vacuum before the hole closes. The entrope can open these holes once every three rounds. The rest of the time, it defends itself with two huge claws (1d8 points of damage each) and a gigantic tooth-filled maw (1d12 points of damage). The strange creature is also immune to the effects of all elements, even ignoring impact damage from thrown boulders or similar attacks. Graybeards know of only two ways to harm an entropy: strike it with a magical weapon of +2 or greater enchantment, or subject it to nonelemtntal-based spells such as cause light wounds, magic missile, and so on.