Magical Guide

A Magical Guide is a character who is magical in some way and appears to help the hero when he or she needs it. Magical guides usually fill the following criteria:
 * 1) They appear when the hero needs help.
 * 2) They are usually deceased and thus act as Spirit Advisors.
 * 3) They are usually related to the character, such as a parent, sibling or Mentors.
 * 4) They have powers of their own and usually grant the hero new powers or restore lost powers.
 * 5) They provide advice or comfort to the hero.
 * 6) They may save the hero's life.

Compare Spirit Advisor.

Anime and Manga

 * Queen Serenity from Sailor Moon fits this perfectly; She is the deceased mother of the titular hero, she restored all of the Sailor Senshi's memories of the past, and she grants Usagi/Serena new powers in the second season.

Literature

 * Played for laughs in The Last Continent; Rincewind is periodically aided/annoyed by a divine being generally known as Scrappy, which can take multiple forms and interferes in his adventure in order to guide him to the fruition of his quest. Even though this is the last thing Rincewind wants.

Live-Action TV

 * God from Joan of Arcadia, in all the many and varied forms he/she/it takes, seems to play this role for Joan, although for what ultimate purpose is unclear.

Video Games

 * The owl Kaepora Gaebora in The Legend of Zelda: Ocarina of Time and its sequel Majora's Mask shows up periodically to give background and direction, although he's so long-winded that players tend to skip his dialogue. To a lesser extent, there are statues (usually owl- or at least bird-shaped) throughout the Zelda games giving hints on difficult puzzles or bosses.