In Ni No Kuni 2 you'll find some familiars called Higgledies that will help you during battle.

There are a total of 30 Stones that you can find to unlock some of them, here's a full list:

- 0:07 Twinkle the Twee

  Location: Jumblewoods

  Item Required: Rugged Fur

  Item Location: Heartlands, Wiggly Way

- 1:26 Popple the Pure

  Location: Jumblewoods

  Item Required: Slumbergull Feather

  Item Location: Makronos, Capaneus's Crypt

- 2:29 Frumious the Flammable

  Location: Tightfit Cavern

  Item Required: Hardwearing Wool

  Item Location: Calmlands, Swift Solutions

- 3:25 Tove the Tenebrous

  Location: Wyvern's Den

  Item Required: Single Cream

  Item Location: Calmlands, Unsung Shrine

- 4:32 Filigree the Flighty

  Location: Cloudcoil Canyon

  Item Required: Munchy Nut

  Item Location: Cloudcoil Canyon, Snaketooth Ridge

- 5:17 Motley the Menace

  Location: Rolling Hills Area, Crosswater Cavern

  Item Required: Snow-White Thread

  Item Location: Rolling Hills, Cloudcoil Canyon

- 7:02 Phantasmagoria the Foul

  Location: Hard Woods

  Item Required: Nightmare Prism

  Item Location: 

- 8:26 Mutton-Bane the Mushy

  Location: Auld Woods

  Item Required: Gunkshrooms

  Item Location: Forest of Niall, Budding Lumberyard

- 9:33 Dirge the Dismal

  Location: Shiverwood Shrine

  Item Required: Twisty Bone

  Item Location: Leucippes' Labyrinth, Pinwheel Flats

- 11:52 Slithy the Spelunker

  Location: Crooked Cavern

  Item Required: Glacier Crystal Cluster

  Item Location: Abyss, Mining Camp No. 4

- 13:57 Whiting the Lighting

  Location: Calmlands / Capstan-upon-Hull Areas, Unsung Shrine

  Item Required: Wonderwater

  Item Location: 

- 15:38 Gabardine the Gawker

  Location: Calmlands / Capstan-upon-Hull Areas, Death's Door

  Item Required: Knight's Brocade

  Item Location: Drylands, Bleachbone Shrine

- 17:10 Mimber the Meanderer

  Location: Calmlands / Capstan-upon-Hull Areas, Hidey-Hole

  Item Required: Sackcloth

  Item Location: Calmlands, Reight Bright Beacon

- 18:11 Tundle the Tropical

  Location: Hydropolis Area, Dampshow Cave

  Item Required: Coral Huebloom

  Item Location: Rolling Hills, Cloudcoil Canyon

- 20:02 Dishcloth the Dragony

  Location: Hydropolis Area, Seaspray Tunnel

  Item Required: Briar Coral

  Item Location: Any Water, Makronos

- 21:00 Haddock the Fishy

  Location: Abyss, 1000 Fathoms Deep

  Item Required: Bright Button

  Item Location: Abyss, Makronos

- 22:28 Teakettle the Toasty

  Location: Splitstone Canyon (Eastern Desert) Area, Bleachbone Shrine
  Item Required: Fluffy Cloth

  Item Location: Drylands, Swift Solutions

- 23:53 Vorpal the Volcanic

  Location: Splitstone Canyon (Eastern Desert) Area, Sunshade Shrine

  Item Required: Sunnysmile Cotton

  Item Location: 

- 25:41 Boss-Woss the Bruiser

  Location: Broadleaf Area, Shrine That Time Forgot

  Item Required: Bolt Eagle Feather

  Item Location: 

- 27:14 Unkimmon the Uncommon

  Location: Broadleaf Area, Sublime Shrine

  Item Required: Coarse-Grained Lumber

  Item Location: Abyss, Makronos

- 29:10 Bumblebizz the Blowy

  Location: Broadleaf Area, Fathomless Forest

  Item Required: Fine Fur

  Item Location: Abyss, Pinwhell Flats

- 30:33 Topturvy the Testy

  Location: Boardleaf Area, Dynafloor n.2

  Item Required: Scented Sap

  Item Location: East Wood, Pinwheel Flats

- 32:26 Slingdby the Scrocher

  Location: Broadleaf Area, Dy

  Item Required: 

  Item Location: 

- 34:09 Malignity the Indignity

  Location: Ice House

  Item Required: Sturdy Bone

  Item Location: Wiggly Way, Forest of Niall

- 35:40 Benison the Bright 

  Location: Freezybones Cave

  Item Required: Enigma Prism

  Item Location: Mining Camp No. 4

- 37:31 Bawbee the Bandit

  Location: Rolling Hills Area, Old Well

  Item Required: Blossomwheat

  Item Location: Pinwheel Flats, East Wood

- 38:45 Dimity the Dastardly

  Location: Rolling Hills Area, Old Well

  Item Required: Forked Tail Bone

  Item Location: Drylands, Jack Frost's Playground

- 39:43 Larrican the Leafy

  Location: Cloudcoil Canyon

  Item Required: Prism Pepper

  Item Location: 

- 40:44 Tilly-Loo the Twinkly

  Location: Rolling Hills Area

  Item Required: Clear Prism

  Item Location: Swift Solutions, Mining Camp No. 1

- 42:31 Clambunctious the Calm

  Location: Abyss, 2000 Fathoms Deep

  Item Required: Bighorn Shell

  Item Location: Fine Fish Market, Right Bright Beacon

For a detailed walkthrough check the video below: