Christian asks: Could a sphere of annihilation permanently kill a tarrasque? I know they regenerate even after being disintegrated, but according to the rules for said artifact, "Any matter that comes in contact with a sphere is instantly sucked into the void, gone, and utterly destroyed. Only the direct intervention of a deity can restore an annihilated character."
The tarrasque, by the words in the Monster Manual, is immune to all death effects and permanent injuries. Although it doesn't list every single thing it's immune to, it's quite clear that it's immune to effects that immediately cause death, or permanent injuries. The Monster Manual makes it very clear that the tarrasque cannot be killed or permanently altered in any way, save for a wish spell when it's driven into unconsciousness. This means that the tarrasque is immune to all effects that cause instant death, including orb of annihilation, suffocation and starvation. If that isn't enough to satisfy you, then face facts: if any of those things could have killed the tarrasque, then they would have done so already. The tarrasque is a legendary unkillable monster, fought throughout time, and there are relatively low level spells, and much easier monsters, that cause suffocation upon targets. If suffocation could drop the tarrasque to unconsciousness then it would have done so, and the same goes for starvation, and even powerful magic effects. The tarrasque is immune to all death effects, and anything that causes death for any reason besides damage is a death effect. Still, the tarrasque isn't immune to teleportation or mind control, so what I'd do is cast polymorph any object on him to turn him into a small rock or something (it'll take several tries and only last 20 minutes, but it'll be worth it), put the rock in a bag of holding, and then stab the bag. The bag will be destroyed, but all the contents will be lost forever (as per the item description). Goodbye tarrasque. Or better yet, gate or plane shift with the small rock to the plane you like least, drop it on the ground and plane shift back/gate back. That plane will officially have a new hobby in about twenty minutes or so.
--Robert
