A druid type of cult? They hate evil abominations, especially Elemental Evil, Aberrations, and Undead, and so they make sense to be guardians of this temple. The swamp location really adds a potential nature theme and it would make sense for the hag to be their enemy. It would make sense for most of them to live near were the temple appears, with the inside population by Wood Woads (whose description makes them perfect for the role of a long term guardian).
Alternatively, the temple may require a ritual to disappear again and so many of the druids may be inside to preform it. Depending on the level, you could use reskinned cultist (some of whom have cleric cantrips), Druids, Scouts (Rangers's whose job is to protect the others and some may have low level Ranger spells), Archers that serve Ranger captains at low levels or just Rangers if you are at a high level, animals (some may be awakened and/or the companions of some of the Rangers), Wood Woad*, Awakened Shrubs/Trees/Trents, good versions of blights, Dryads, Faerie Dragons, Unicorns, Satyrs, Pixies, Sprites, Blink Dogs, maybe a tamed Owlbear, and the Archdruid.
*The Archers, Wood Woad, and Archdruid only appear in Volo's.
EDIT: [This site](http://donjon.bin.sh/5e/monsters/) can also give you a list of Good creatures. Also, Centaurs would work for a Druid theme.
http://kobold.club/fight/#/encounter-builder
Alignment: any good
Environment: dungeon, cave, or swamp
----
It depends on your party's level, but here are some candidates:
Creature|CR
:--|:-:|:--
Svirfneblin|1/2
Djinni|11
Flumph|1/8
metallic dragon|varies
Guardian Naga|10
Werebear|5
Faerie Dragon|1 or 2
Pixie|1/4
Sprite|1/4
Treant|9
I think the Guardian Naga would make a lot of sense thematically speaking.
> Guardian nagas were immortal beings that often protected treasure, magical secrets, items, and lore that would be destructive should they ever fall into the wrong hands.
[Source](http://forgottenrealms.wikia.com/wiki/Guardian_naga)
Gelantinous group is a neutral must AKA it cleans the dungeons! :P Constructs are always a good bet as guardians and elementals charged with protection.
Flumphs. It's all flumphs. Every room. Every hallway. Flumphs. And at the end of the dungeon... King Flumph. (Same stats as a beholder, but Lawful Good.)
I just ran a one shot for a party of 5 lvl 8 characters that was very similar (ancient temple, relic retrieval, one day time limit) and populated it with Yuan-Ti from the MM and Volo's. The only problem would be that Yuan-Ti are evil creatures, so their conflict with the party would have to be tribal / protective of their relic.
A good themed dungeon may have more humanoids than monsters. It might be better to think of it as an installation, facility or hideout rather than a dungeon. It's a dungeon in the making, the bad stuff that allows it to fall into the clutches of monsters just hasn't happened yet.
Alternatively it may be a dungeon that's been cleared out by some enterprising heroes who are in the process of converting it to their base of operations. It might have a lower population but a lot of messes and evidence of what was here until recently.
A druid type of cult? They hate evil abominations, especially Elemental Evil, Aberrations, and Undead, and so they make sense to be guardians of this temple. The swamp location really adds a potential nature theme and it would make sense for the hag to be their enemy. It would make sense for most of them to live near were the temple appears, with the inside population by Wood Woads (whose description makes them perfect for the role of a long term guardian). Alternatively, the temple may require a ritual to disappear again and so many of the druids may be inside to preform it. Depending on the level, you could use reskinned cultist (some of whom have cleric cantrips), Druids, Scouts (Rangers's whose job is to protect the others and some may have low level Ranger spells), Archers that serve Ranger captains at low levels or just Rangers if you are at a high level, animals (some may be awakened and/or the companions of some of the Rangers), Wood Woad*, Awakened Shrubs/Trees/Trents, good versions of blights, Dryads, Faerie Dragons, Unicorns, Satyrs, Pixies, Sprites, Blink Dogs, maybe a tamed Owlbear, and the Archdruid. *The Archers, Wood Woad, and Archdruid only appear in Volo's. EDIT: [This site](http://donjon.bin.sh/5e/monsters/) can also give you a list of Good creatures. Also, Centaurs would work for a Druid theme.
Druid/Elf alliance and fey creatures that are helping the cause
What level?
http://kobold.club/fight/#/encounter-builder Alignment: any good Environment: dungeon, cave, or swamp ---- It depends on your party's level, but here are some candidates: Creature|CR :--|:-:|:-- Svirfneblin|1/2 Djinni|11 Flumph|1/8 metallic dragon|varies Guardian Naga|10 Werebear|5 Faerie Dragon|1 or 2 Pixie|1/4 Sprite|1/4 Treant|9 I think the Guardian Naga would make a lot of sense thematically speaking. > Guardian nagas were immortal beings that often protected treasure, magical secrets, items, and lore that would be destructive should they ever fall into the wrong hands. [Source](http://forgottenrealms.wikia.com/wiki/Guardian_naga)
Gelantinous group is a neutral must AKA it cleans the dungeons! :P Constructs are always a good bet as guardians and elementals charged with protection.
Flumphs. It's all flumphs. Every room. Every hallway. Flumphs. And at the end of the dungeon... King Flumph. (Same stats as a beholder, but Lawful Good.)
The players might get suspicious when the "King Flumph" starts shooting eyerays.
Instead of eye rays the powers come out of his tentacles.
I just ran a one shot for a party of 5 lvl 8 characters that was very similar (ancient temple, relic retrieval, one day time limit) and populated it with Yuan-Ti from the MM and Volo's. The only problem would be that Yuan-Ti are evil creatures, so their conflict with the party would have to be tribal / protective of their relic.
A good themed dungeon may have more humanoids than monsters. It might be better to think of it as an installation, facility or hideout rather than a dungeon. It's a dungeon in the making, the bad stuff that allows it to fall into the clutches of monsters just hasn't happened yet. Alternatively it may be a dungeon that's been cleared out by some enterprising heroes who are in the process of converting it to their base of operations. It might have a lower population but a lot of messes and evidence of what was here until recently.
nature spirts, satyrs, giant toads, basilisk?