This was always my favourite class back in the time when I played, and I wonder whether I can tribute it in a pathfinder game.
There are many ways to pull it of, but none to reflect the shear varity that the DIII skill system allowed.
That's what I found so far:
My favourites:
Grasp of the Dead -> refluffed Black Tentacles, easy
Toad of Hugeness (Hex) -> Giant Frog Animal Companion (sucks), probably Mammoth Rider needed
Spirit Walk -> Ancestor Oracle actually has this. And there are ome similar spells I guess.
Rain of Frogs -> This spell exists, but is rather weak
Fetish Army -> urgh. Mad Monkeys??
soul harvest, very difficult mechanic
The good Stuff:
Gargantuan -> Eidolon, any questions?
Summon Zombie Dogs -> oh, well, summon dire wolves
Bats -> hm, refluffed burning hands or the like. A summon swarm spell might also be ok.
Mass Confusion -> Confusion?! or Witch
The rest:
Big bad vodoo ?
all the Decay stuff is some kind of spell I guess
Fire Bomb -> uh, Alchemist! Investigator and Rogue can also do this
Poison Dart -> poisoned darts!
So I see some very different builds here, depending on what to focus on. Summoner does give me a lot in this list, but is only a medium caster. Shaman, Witch, Druid and oracle are also contenders, especially with some VMC.