The NPCs are well know in this server to have an aggressive follow distance. In fact, as long as you don't fuck up their path finding or get out of minimap range of them I believe they continue to follow.
Yes, I wrote a half arse explanation.
This spider had respawned on the bridge over the Lum very near to the memorials, it wasn't wander distance. Is it still there? Does it still be aggressivness to a player? No, it had spawned and automatically had gone after a player npc level 1 memorial npc I might add which was very close to where this giant spider spawns.
This was the result of my own experience seeing a now missing spider going after this now missing memorial npc.
(http://.http://i.imgur.com/noF8YnE.jpg)
omg(click to show/hide)
he died! :l