Beltane, Beltaine, Bealtinne was the official beginning of summer among the ancient Celts. Today it has been marginalized as May Day and not a traditional holiday in the modern world as it was among the ancients. The celebration honored the old Celtic deity Bel (possibly related to Beltene, god of the dead). The ancient Celts only recognized two seasons of the year, one being Beltane (summer) and the other Samhain (winter).
Beltane marked the days when the good fairies of summer reigned, and Samhain was a time when the darker fairies ruled the land. The fairies were believed to hold a grand festival, and even attempt to steal fire from the sacred bonfires Celts lit at this time. Every seven years the fairies fought for the best ears of grain on Beltane. It should be noted that evil fairies love to spoil the first batch of beer, so a cross had to be drawn in the foam to deter them. Bad fairies were believed to cause blight, but most of the time saved their nasty blights for Samhain (October 31st, now known as Halloween).
One of the most famous fairies would be Puck, who gained notoriety through Shakespeare’s play, A Midsummer Night’s Dream. He was known as a mischievous English fairy who loved to play tricks on humans—what fools these mortals be. Often described as a jester to the fairy court, he appears as such in Shakespeare’s play. In the Medieval Era he was considered a demon, but was also associated with one Robin Goodfellow, a figure who may have led to the legend of Robin Hood. Puck could be talked into being a good house fairy, but could be downright ornery and lead travelers astray. He could change into a horse and trick innocent people into riding him, getting them lost. Such fairy mischief was often referred to as being “pixy-led.”
In some sources, Puck was similar to Pan/Silvanus, with the legs, lower body, and horns of a young goat. He also played musical pipes just like Pan and the other ancient goat spirits. Being connected with summer time, Puck was never seen between Samhain and Beltane. He could also change into an eagle or a donkey. He had many incarnations and names, such as Pwca, Pooka, Puge—even Puke! Sometimes the name Puck was used as a term for the devil or some other demon.
Then there’s Puk, a Baltic house fairy that could appear as a small dragon. Known for retrieving stolen treasure for the master of a chosen household, he was likely just another version of Puck, as there seem to be versions of Puck throughout fairy folklore.