For necromancers killing this guy for Harvester quest, Letheos post from 2002 is probably the most on target:
"Ok, i have seen alot of post on this sublect but all miss the obvious. Just go into the pits on the side of the blood pits. The only thing in there is the Fungus guy. Here is the secret...nothing else will aggro you in the pit. All you have to do to get out with out dying is GATE...why is it that casters always try to walk out?? We all have the one save all port spell so why dont we all try using it??
As far as IVU against a terro or werebat...they are not undead and will see right thru it. Its a waste of time and EXP to think that you can run past them with it on. Of course if there is a necro that is trying to take on the Fungus man and he is aggroed...FD is the best life saver you got."