Pixie 

Pixie folklore, according one theory of some scholars, is thought to be from an ancient tribe of people called "The Pict Tribe".  They were known as "Real Life Pixies" from southern England and wore blue war paint 

Another theory is that they were a race of very small people that lived on an island near Southern England. 

In some places, they are sometimes confused with Fairies and Sprites but they should not be confused.  In this picture you can see the similarities. The Pixie is considered a creatures of the woods or meadows.  A Sprite is a creature of the water.  They are sometimes referred to as Water Sprites.  A Fairy on the other hand is not as nice.  Though similar, the two are considered enemies.

Do you want to see a Pixie?
Take a walk along England’s beautiful southern coast and you may be charmed by more than just pretty wildflowers, mystical stone rings, and the blue, blue ocean. Pixies also roam the countryside, and if you happen to have a pretty scrap of ribbon or a clever verse of poetry for them, they might just invite you to join in with one of their giddy dances or send you along your way with a blessing over your head.

What Is A Pixie?

Pixie, pizkie, piskie and pigsie are names that are sometimes used.   There are scholars that believe that the word is from a Swedish word for tiny fairy.  In Cornwall,  England which is the place where they were first written about it is thought that these names may have a Celtic origin and they are closely related to the Irish and Scottish SosSi. 

Traditional folklore says they are magical and  like tiny little kids that like to get together in groups so as to dance and wrestle all night long. They are small enough to fit in your hand or sit on a mushroom.

A poem by  Samuel Minturn Peck:

‘Tis said their forms are tiny, 
     yetAll human ills they can subdue,
Or with a wand or amulet
     Can win a maiden’s heart for you;
And many a blessing know to stew
     To make to wedlock bright;
Give honour to the dainty crew,
     The Pixies are abroad tonight.

Pixie Day

There is a town, Ottery St. Mary, in the county of Devon in England.  This county is sometimes refereed to as Devonshire in history and folklore.

In this town they celebrate Pixie Day, from an old legend.  This is the day Pixies were kicked out of town and sent to "Pixie's Parlor".  "Pixie's Parlor"  is the name given to the local caves.

In the legend, a town Bishop decided to put bells from Wales in the local church.  The Pixies decided this would be disastrous, so they put a spell on the road leading to town.  They set it up so the Monks bringing the bell would be diverted to a cliff.  As one Monk was about to go over the cliff, he shouted "Bless My Soul" and the spell was partially broken. 

The spell however allows that one day a year in June, the Pixies can capture the Bell ringers and put them in Jail in the "Parlor".  For this event the town erected a "Parlor" jail in the town square. They can only be rescued by the local Vicar.  The legend is reenacted by the local Cub and Boy Scouts.

Aos Si Definition
https://en.wikipedia.org/wiki/Aos_Sí
The aos sí is the Irish term for a supernatural race in Irish mythology and Scottish mythology comparable to the pixies or fairies or elves. They are said to live underground ...