13,394 NPCs

Classic reference; current Forever availability is unconfirmed.

NPCLevelTitleZone
Outlands Test Dummy Warrior 5858
Outlands Test Dummy Warrior 5959
Outlands Test Dummy Warrior 6161
Outlands Test Dummy Warrior 6262
Outlands Test Dummy Warrior 6463
Outlands Test Dummy Warrior 6663
Outlands Test Dummy Warrior 6863
Outlands Test Dummy Warrior 6963
Nightmare Illusion60
[PH] Luis Barriga60
[PH] Luis Test NPC45
Outlands Test Dummy Warrior 5454
The Banshee Queen1
Blackwing63
Vulculon UNUSED62Abyssal Council
Male Ghost1
Female Ghost1
Trick - Critter1
Dream Fog60
Demented Druid Spirit60
Spirit Shade60
Shade of Taerar63
Ancient Mana Spring Totem1
Moonkin (Druid - Night Elf)1
Moonkin (Druid - Tauren)1
Steam Tonk1
Giant Eye Tentacle60
RC Blimp <PH>1
Corrupted Water Elemental60
Blue Baby Murloc1
Purple Baby Murloc1
White Baby Murloc1
Pink Baby Murloc1
Green Baby Murloc1
Murki1
Spirit Totem35
RC Mortar Tank <PH>1
Tonk Mine60
Halloween Pirate Captain1
Halloween Undead Pirate1

Classic reference data from QuestieDB (Forever data, commit c5de61a), with positions on Forever's zone maps. It doesn't confirm that an NPC, location, quest or item is in Forever.