From The Mana World

Server reserved npcs

ID Description
-1 Used only for map-less (floating) npcs
45 Displays a warp tile (depending on the client settings). Does not display warp particles
139 Used by Hercules for hidden warps
722 Displays a debug warp tile (used by battleconfig.warp_point_debug). Does not display warp particles
127 Displays a transparent non target-able npc. Used by tmwa for area effects (magic) and specialeffect
32767 NPCs with this ID exist only server-side and are not sent to the client. Usually you should prefer this over 127. However if your npc need to display particle (specialeffect) you should use 127


Custom special npcs

ID Description
400 Displays a transparent target-able npc


TODO: add a transparent target-able npc with pickup cursor
TODO: add a transparent target-able npc with fight cursor