There are currently 193 NPCs with name "null" and one or more models.
Most of these are not interesting to players at all, like this cow and the walking chairs in Draynor Manor.

However, a few of these are probably used by players to true tile/radius mark attacks in PvM situations.
NPC IDs |
PvM encounter |
Images |
7556, 7557 |
CoX Great Olm
(no idea what this is marking, nobody is probably using this) |
https://chisel.weirdgloop.org/moid/npc_id.html#7556,7557
|
8386, 10846, 10863 |
ToB Verzik P3 tornadoes |
https://chisel.weirdgloop.org/moid/npc_id.html#8386,10846,10863

|
9025, 9039 |
Gauntlet Hunllef tornadoes |
https://chisel.weirdgloop.org/moid/npc_id.html#9025,9039

|
9669, 9670, 9671, 9672, 9673, 9674 |
Hallowed Sepulchre swords and bolts |
https://chisel.weirdgloop.org/moid/npc_id.html#9669,9670,9671,9672,9673,9674

|
10878, 10879, 10880, 10881, 10882, 10883, 10884, 10885, 10886 |
Thralls |
chisel moid #10878,10879,10880,10881,10882,10883,10884,10885,10886
|
11765, 11766 |
ToA warden
(not sure what this is) |
https://chisel.weirdgloop.org/moid/npc_id.html#11764,11765,11766,11767
|
12198 |
DT2 Duke Sucellus gas vents |
https://chisel.weirdgloop.org/moid/npc_id.html#12198

|
12222 |
DT2 Awakened Leviathan tornado |
https://chisel.weirdgloop.org/moid/npc_id.html#12222

|
12227, 12229 |
DT2 Vardorvis swinging axes |
https://chisel.weirdgloop.org/moid/npc_id.html#12227,12229

|