Arianwen is a tall, slender caeltir with shoulder length black hair that glints with green in the sunlight. Her eyes are unfathomable, sometimes appearing blue, at other times green, and her complexion is pale yet healthy. She moves with grace in near silence and seems to drift effortlessly though terrain that would hinder any man.
Arianwen wears an ornate circlet on her brow bearing a smooth green gem, and a green leather torque circles her neck. Her clothes are simple yet finely made: a weatherproof olive green greatcloak over a light green tunic and brown leggings, soft doeskin boots on her feet.
Arianwen is a member of the Druidic Circle of Northumbria and a close ally of Myrddin. She tends several great oak groves between York and the Scottish border, and is able to travel rapidly between them as a result of her druidic powers. Her greatest affinity is with wolves: she is able to assume the form of a large female wolf, and is often accompanied by a wolf pack she has befriended.