I’ve covered several sorts of fairy on my blog, but so far I hadn’t said anything about the spriggan, which I believe were mentioned in the most recent Fairyland book. They appear to be a very localized kind of fairy, traditionally appearing only in Cornwall. Spriggans are grotesque little creatures known to be particularly malicious.
They were believed to cause bad weather and illness and to steal babies, as well as luring humans to their doom. They inhabit ruins and guard treasure, often stuff they stole from humans. One aspect for which spriggans are particularly known is their ability to take on gigantic size at will. Fortunately, they can be driven away if you turn your clothes inside out.
As with many beings from folklore, the spriggan has been adapted into the world of role-playing and video games. They appear in the Elder Scrolls and Skyrim games, and Final Fantasy XIV makes them creatures powered by magical stones.
Chrono Cross has a spriggan character named Sprigg, a tiny old lady with blue skin and pointed ears whose experiments in magic resulted in her being trapped in the Temporal Vortex.
When Serge ends up there, he finds Sprigg living in a tree, and can recruit her for his party. While she doesn’t appear to have the ability to expand her natural form, she can take the shapes and abilities of defeated monsters. Her association with trees might stem from the similarity of the word “spriggan” with “sprig,” basically a twig with leaves.