Mark Chance said:
My brain is shutting down. Help me make up a slaadi lair. Top dog slaad is a gray. Party's average level is mid-teens, but they are strong against chaotic foes. Lair is within the domain of Spider, a trickster avatar of Ralishaz.
If the slaadi know the PCs are coming, then area effect lingering spells might be fun -- a corridor filled with cloudkill, a chain lightning linked to a hidden glyph, a maze spell, etc.
Since this lair is located in the outer planes, does it have access to the ethereal plane? if so place some rogue types in the ethereal guarding an area. Pop they come ethereal and sneak attack.
What kind of places would be in a slaadi lair? Perhaps an art gallery where the pieces continually change form, occasionally into something dangerous. Imagine a crystalline spire slowly turning into a crytsal statue that turns into an iron golem (that attacks!) that turns into a stone golem (continueing to attack) turning into a stone rhinocerous (again, attacking, that turns into a pile of stone blocks (and stops attacking).
A picture of a medusa that animates when considered/searched...
An area where colors change and shift -- the red-haired fighter becomes yellow and blue checked hair color.
A tavern/bar where the slaadi relax?
A torture/experimentation area... How many times can we shock the dire crocodile before it dies?
Just off the top of my head.