I've had my PCs atop several dead gods, and inside another. Now all of those occasions were on the Astral, but the general situation should be similar enough.
Dead gods don't go into their twilight oblivion quietly, and every so often they might have memories, or bits of the former deific power spontaneously manifest on or around the petrified corpse. Gods of nature might sprout forests, or possibly carnivorous animals who want to use outsiders as mulch for said forests. They might manifest aasimon (angels) who might be unaware that their patron is already dead, and that they're just a hollow echo of that patron's power. Such deific servitors might be aware of it, and they might mourn and lament their passing, or seek to convert anyone they find, knowing that an influx of true belief is their only chance at independant survival, because at any moment the dead god's manifestations could vanish for years or millennia, and them with it.
It depends on the flavor, alignment, and nature of the dead god in question, but it might be surrounded by proud visions of past glories, a sad reflection of what has passed and been forgotten, or bloodthirsty madness as bits of the god's mind seek to clamber free of the grave.
And then there are the parasites who might come to worship the deific husk, or desecrate it, or feed on those who come to do either.
