Bad Code
 global shaman = getShaman(TRIBE_BLUE);

 def OnTurn()
 {
     if (!shaman.isNull())
     {
         log(shaman.ThingNum);
     }
 }
Reason: Shaman may not exist on the next turn and will not become null.

Correct Code
 global shamanProxy = ObjectProxy(getShaman(TRIBE_BLUE));

 def OnTurn()
 {
     if (!shamanProxy.isNull())
     {
         var t_thing = shamanProxy.get();
         log(t_thing.ThingNum);
     }
     else
     {
         log("Shaman has died");
     }
 }