Goblin

Just like the names fairy and elf, goblin has a different meaning and different usage for different people. Only several creatures were seen as goblins in Celtic folklore. But goblin is probably not the right description. Some goblins can appear benevolent, while others are mischievous or malevolent creatures.

In Irish folklore, the dullahan and cluricaune were considered to be goblins. And so was the Welsh bwgan.

In Irish myth about Finn Mac Cumhaill, there was Aillén Mac Midgna, better known as Aillén the Burner, who was considered to be a goblin. On Samhain-eve, Aillén would come playing his harp, whose melody would put everyone to sleep. Then he could cause part of the destruction of Tara. There was no description of what he looked like. See Fenian Cycle.