The scenario is as follows:
- Shem the Wizard first casts Conjure Elemental into a Glyph of Warding, setting it up to summon a Fire Elemental.
- Shem triggers the glyph, summoning the elemental with no need to concentrate on it. The elemental is friendly to them for the duration (one full hour), and is set to vanish again at the end of the hour.
- Shem casts True Polymorph on said elemental, transforming it into, for simplicity's sake, an Air Elemental.
What happens at the end of the one hour when the original Conjure Elemental expires?
What if Shem in step 3. true polymorphs the elemental into a chamberpot?
A good answer would address both (a) if the creature remains after the original summoning duration expires and (b) if the creature is friendly towards the caster in its transformed state (before and, if it remained, after the duration of the original summoning ending).
PS: I’m aware that allowing the polymorphed creature to permanently stick around would be exploitable and would allow you to build an army of minions, one a day. And as a DM I’d shut that down. But on spell level 9 you already can create unlimited numbers of conjured creatures with the Simulacrum exploit, so I’m not concerned about that. I’m curious what would happen here under RAW.
Best Answer
This is a question about the term "game statistics". True polymorph says:
So your question is, simply: is "this creature disappears when the conjure elemental spell ends" a game statistic? If so, it is overwritten by true polymorph; if not, it isn't.
We have a whole question about the definition of "game statistics": What all is included in a creature's game statistics? and the above spell effect is not a game statistic.
So the creature still vanishes even if polymorphed.
You've separately asked what happens with the lines from Conjure Elemental about the creature being friendly or hostile. These lines are also not part of the creature's "game statistics," so they also are not overwritten by true polymorph.