Yeah, that would be a problem. Still, linked-lists are not the best choice. If you are going to store all mobs(npcs+players) you probably want them stored in a r-b binary tree based on id instead of a linked-list. Hell if you want store them in a linked list but have a way of referencing them better than iterating through the linked list.
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++[>++++++<-]>[<++++++>-]<.>++++[>+++++<-]>[<
+++++>-]<+.+++++++..+++.>>+++++[<++++++>-]<+
+.<<+++++++++++++++.>.+++.------.--------.>+.
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