Arthen
From The Green Hills Series
Arthen is hinted at in Book 3 - Green Hills and Fairy Bells, and becomes a prominent character starting in Book 4 - Green Hills and Holy Wells. At 6'5", he is very tall, and considered a giant by tylwyth teg standards. It is because of this (and Mr Fuchs's inability to pronounce his gwragedd annwn name, Fuchs calls him "Arthen," as arth means bear in Welsh.