Wanderer has the typical appearance of every Soul: a reflective silver living ribbon with nearly a thousand thin feathery attachments. Nevertheless, her movements are considered particularly graceful. She is several thousand human years old. When inhabiting Melanie's body, she bears all of Mel's physical characteristics. Later in the book, she is implanted into the body of a 17 year old girl, previously occupied by Pet, who is petite and delicate with golden hair, freckled skin with a type of grayness with it, gray eyes, a dimple in her chin and shorter than Melanie. Although she views herself as a parasite, Ian tells her,"I held you in my hand, Wanda. And you were so beautiful.", affirming that he loves her for who she is, not for her physical form.
Wanda is very different to Melanie. She is selfless and always think about what's the best for her friends and other people. Wanda is very polite even in the presence of someone she doesn't know.
The most important thing about her is that her friends, especially Jamie, are always happy while they're around her.