There are a total of 8 NPCs in Inkwell Isle Extra. The NPCs consist of Lariat, an anthropomorphic surfer shark, Eggy, a baby bunny, Alice, a school girl, Kaiser, a wizard, Riku, a girl from the 1980's, Cryptic Kyle, an anthropomorphic blue leopard, May Anne Hayes, the owner of a restaurant in Inkwell Isle Extra, and Stuart, a French artist.
NPC information
Lariat
Species: Humanoid shark
Gender: Male
Placement on the map: In front of Ravenous Russell's boat, which is next to the goth/emo high school.
Sidequest: Collect 5 stars that are scattered around the isle.
Reward(s): Airplane variants of Charge and Spread
Eggy
Species: Bunny
Gender: Female
Placement on the map: On a patch of grass in one of the sunny areas of the isle.
Sidequest: Go through a shortcut to another area of the isle.
Reward(s): Airplane variant of Chaser
Alice
Species: Angel
Gender: Female
Placement on the map: Not far away from the target that leads to Strained Studio.
Sidequest: Find her MP3 player.
Reward(s): Piano version of the Inkwell Isle Extra theme
Kaiser
Species: Human
Gender: Male
Placement on the map: Not far away from the airport, where Hale Copter is fought.
Sidequest: Defeat Hale Copter in either Simple Mode or Regular Mode.
Reward(s): Two airplane super arts
Riku
Species: Human
Gender: Female
Placement on the map: Next to her family's travel van.
Sidequest: Complete Rainy Rankle, regardless if all 5 coins are collected or not.
Reward(s): 3 coins
Cryptic Kyle
Species: Humanoid blue leopard
Gender: Male
Placement on the map: Next to the cemetery, which has a target on the ground that leads to Gruesome Graveyard.
Sidequest: Get an A-rank or higher on Gruesome Graveyard, with all 5 coins collected.
Reward(s): Marie (a playable character)
May Anne Hayes
Species: Unknown (until her creator confirms what she is)
Gender: Female
Placement on the map: In front of her restaurant.
Sidequest(s): Defeat The Primitive Prisoners in either Simple Mode or Regular Mode.
Reward(s): Tim Tropics (a playable character)
Stuart
Species: Anthropomorphic baguette
Gender: Male
Placement on the map: Next to the easel, where he is painting something.
Sidequest: Collect 2 paint buckets.
Reward(s): Ivory (a playable character)
Object locations
Stars
1. To the right side of Francis Stein's science lab.
2. Next to the van.
3. In front of Snow Queen Sarah's igloo.
4. Right beside the Die House that allows the player to go back to Inkwell Isle 3.
5. Behind a bush.
MP3 player
1. On the sidewalk near one of the sunny areas of the isle.
Paint buckets
1. Behind the order station that is located at the left side of May Anne Hayes' restaurant.
2. Not far away from the target that leads to Vexatious Volcano.