Nuls
Nuls 
are green, octopus-like creatures that inhabit the islands of Big Adventures Park. They can be found in every region except 
Icy Peak. Nuls are silent creatures that do not talk but are often helpful to the residents of the park. Certain Nuls will help run shops while Island Residents are occupied with other activities. Most Nuls can be interacted with to have hats put on them or taken away, and Nuls are the only characters that can wear the 
Nul Ghost Costume. Within the 
City Town region, 
Purple Nuls reside around the area.
Special Nuls
These Nuls have special functions compared to regular Nuls found across the island.
Game Nuls
These Nuls help run the mini-games found in 
Spooky Swamp, 
Rainbow Reef, 
Gemstone Mountain, 
Mount Hothead, and 
Merry Meadows. They wear a red visor and are always stationed at their respective mini-game locations. The hats on these Nuls cannot be changed out.
Curator Nuls
These Nuls run the Nature Preserve and the Critter Corrals. Curator runs the Nature Preserve, Curator Jr. runs the Cloud Island Critter Corral, and Curator Sr. runs the Merry Meadows Critter Corral). They wear 
Critter Catcher Hats and cannot have their hats changed. Interacting with the Curators allows the player to deposit Critters into the preserve system, which automatically places the critters in the biome that matches their biome of origin.
Witch Nul
This Nul shows up before and during the "Re-Haunt the Spooky Swamp" quest. It wears a 
Witch Hat and prevents the player from entering the area unless they are wearing a Witch Outfit. Once the player enters wearing a witch outfit, it leaves and is not seen again in-game.
Propeller Hat Nul
This Nul appears during the "Cinnamoroll is Missing" quest. After 
Cinnamoroll asks the player to find the 
Mailbox Key on the Airplane, the player is given a 
Propeller Hat to put on a Nul near the Resort Plaza fast-travel point. Once done, this Nul can take the player up to the Airplane when requested. It is currently the only way to return to the Airplane in-game.
Nul Boat Nuls
These Nuls come in pairs and ride around on boats. The player cannot interact with these Nuls. The Rainbow Reef Nul boat travels around the interior coastline of Friendship Island, passing by all of the piers that point inward. The Spooky Swamp Nul boat travels around the rivers of the Swamp.
Ghost Tour Guides
The Ghost Tour Guides are the Nuls by the Ghost Tour Ride that wear the Nul Ghost Costume by default. Their special title is known because of a multiplayer friendship quest.
Collector Hat Nul
This Nul appears during the "Terra Nul" quest series. After 
Pochacco will then gift the 
Collector Hat to the player, the player must then give the Collector Hat to the Nul standing outside of Small Gift Big Smile. Once done, the player can ask the Collector Hat Nul for help in gathering various materials. The materials can be collected from the 
Collection Box the following day.
Sprinkler Hat Nul
The player will receive the crafting plans for the 
Sprinkler Hat during the "Friends of the Flowers" quest. The player must craft the Sprinkler Hat and put it on a nul. Once done, the player can ask the Sprinkler Hat Nul for help in watering flowers.
Photo Op Nuls
These Nuls appear during the "Picture Day" quest. Around the island will appear Photo Op Nuls, wearing the 
Photo Op Hat. They will be at 12 different Photo Ops locations. When interacting with the Photo Op Nul, the player can choose Island Residents and Island Visitors to take a photo with them!
City Town Nuls
These Nuls populate the City Town region. They differ from their regular Nul counterparts — instead they're purple!
Gallery
A map with all of the Nul locations.
Player interacting with the Witch Nul.
Player interacting with a Game Nul at the Gem Match mini game.
A player interacting the the Propeller Hat Nul.
A player waving to the Nul Boat in Rainbow Reef on the north side of Cozy Islands. (Credits to @SharkTheFwisherman)
Location of the Nul Boat in Rainbow Reef on the north side of Cozy Islands. (Credits to @SharkTheFwisherman)
A player waving to the Nul Boat in Rainbow Reef, standing at the end of Chococat's Pier in Seaside Resort. (Credits to @SharkTheFwisherman)
Player avatars posing with a Ghost Tour Guide.
A player interacting with the Collector Hat Nul.
A player interacting with the Sprinkler Hat Nul.
A player standing near a Photo Op Nul.
A player standing near a City Town Nul.
