13,394 NPCs

Classic reference; current Forever availability is unconfirmed.

NPCLevelTitleZone
Pat's Firework Guy - GREEN1
Pat's Firework Guy - PURPLE1
Pat's Firework Guy - RED1
Pat's Firework Guy - YELLOW1
Pat's Firework Guy - WHITE1
Pat's Firework Guy - BLUE BIG1
Pat's Firework Guy - GREEN BIG1
Pat's Firework Guy - PURPLE BIG1
Pat's Firework Guy - RED BIG1
Pat's Firework Guy - WHITE BIG1
Pat's Firework Guy - YELLOW BIG1
Lunar Firework Credit Marker60Darnassus
Lunar Cluster Credit Marker60Darnassus
Lunar Festival NE Vendor (PH)1
Lunar Festival NE Harbinger1
Vanquished Tentacle60
Giant Spotlight60
Tentacle Portal63
Giant Tentacle Portal63
Pat's Firework Cluster Guy (BLUE BIG)1
Pat's Firework Cluster Guy (GREEN BIG)1
Pat's Firework Cluster Guy (PURPLE BIG)1
Pat's Firework Cluster Guy (RED BIG)1
Pat's Firework Cluster Guy (WHITE BIG)1
Pat's Firework Cluster Guy (YELLOW BIG)1
Lunar Festival Reveler1
Pat's Firework Cluster Guy (ELUNE)1
Viscidus Trigger1
Toxic Slime60
Poison Cloud60
Hive'Zara Hornet61
Vekniss Hatchling60
Buru Egg Trigger60
Alterac Valley Battlemaster1
Naxxramas Template1
[PH] Valentine Reveler, Male1–60
[PH] Valentine Reveler, Female1–60
[PH] Eric Maloof Test Guy1
Sam's Test Dummy 11
Sam's Test Dummy 21

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.