Polari

Polari is an elderly dark brown Luma who appears during the events of Super Mario Galaxy. Said to be one of the oldest Lumas in existence, Polari serves as Rosalina's most trusted adviser. Having extensive knowledge of the Comet Observatory, Polari serves as a guide of sorts to Mario, showing him a map of all of the galaxies visible from that location.

Polari shows certain similarities to Toadsworth. He is highly protective of the person he advises, and is additionally shown to have wisdom that proves useful to Mario on his adventure.

Trivia

 * Polari's name comes from the star "Polaris", also known as the North Star.
 * Polari is never mentioned by name in-game; the only place his name appears is in the Super Mario Galaxy instruction booklet.
 * In Mario Kart Wii, Polari does not appear along side Rosalina. Instead, it is a regular unnamed Yellow Luma. It is possible Polari is in charge of the Comet Observatory while Rosalina is racing.
 * It is possible that Polari's coloration is a reference to brown dwarfs, objects similar to stars that are too small to start hydrogen fusion.
 * It could also be a pun of polarity, which is the brightness of a star.