Sparkler

Sparkler is a unicorn background pony and one of the first ponies the audience meet in 's first episode, when Twilight passes her and Lyra on her way to the palace library. She is also sometimes called Amethyst Star after a toy that resembles her.

Her first speaking role happens in the episode The Mysterious Mare Do Well, where she becomes an unwilling part in Rainbow Dash's attempts to demonstrate heroism. In that scene, she shares a picnic spread with Tootsie Flute, a filly occasionally assumed to be either her daughter or the adopted daughter of Lyra and Bon Bon.

Sparkler's personality in fan labor is not well defined. She is a fairly frequent subject of non-narrative fan art, but with one exception, she has not had much impact in fan fiction; for instance, she is not part of the character search mode on FIMFiction or the Pony Fiction Archive.

However, since a "canon" appearance in the episode paired her with Dinky Doo in a competition, some fans speculated about a special connection between the two: sometimes they're connected through a mentorship program (example), sometimes they're depicted as sisters outright (http://awildfantasy.deviantart.com/art/Adventure-Time-with-Dinky-and-Sparkler-268580455 example). The fanfic Shimmer, in which Sparkler is a main character, casts her as the adopted daughter of Derpy Hooves.