Lyra Heartstrings

Heartstrings is the name of a unicorn background pony, frequently used by a layout artist for background gags. Her cutie mark is a lyre. Her name is not mentioned in the show, instead it first appeared in the accompanying pamphlet of a mystery pack toy released in early November 2011.

Depiction in the series
Heartstrings is frequently used by one of the show's layout artists for background gags, such as bouncing on clouds, jumping around excitedly, drinking from a cup, or slouching like a human on a park bench. She cries when the parasprites eat her pie in Swarm of the Century. A partial list of her appearances is specified in the charts below.

Heartstrings is frequently seen alongside Bon Bon. The pairing has been explained by a layout artist to be mostly coincidental and based on aesthetic considerations as far as season one is concerned. The two are depicted talking in crowd scenes, enjoying a snack, or watching Applejack and Rainbow Dash during the Iron Pony Competition.

In Lesson Zero, at one point in the background she physically fights one-on-one against Bon Bon for the possession of Smarty Pants; the two stand next to a well in Secret of My Excess and are surprised when Derpy Hooves pops out of the well. A unicorn with her coat and eye color is disguised as a mummy in Luna Eclipsed. Appears in Hearts and Hooves Day standing next to Bon Bon in the village shot and appears shortly in Applebloom's fantasy scene.

Variants
A number of background pony variants using Heartstrings' basic design and color scheme exist. They are included in the appearances table below. The most common of these is an Earth pony that matches Heartstrings exactly, safe for the absence of a horn; this design is primarily used in crowd shots. A unicorn variety with red eyes appears occasionally in scenes where Heartstrings runs around town, either on her own - as in Applebuck Season - or as part of a throng of other ponies, as in Boast Busters and The Ticket Master. Not every "running Heartstrings" has red eyes, however; she does not in Hearts and Hooves Day, and while she has red eyes for most of the race in Fall Weather Friends, they are yellow at the beginning of the race in that episode.

An Earth pony with Heartstrings' coat, mane color and mane style, but red eyes, appears in two episodes: Over a Barrel and Luna Eclipsed. In both cases, she wears a bonnet. A Pegasus variant with Heartstrings' color scheme but wings and a different mane style appears briefly in the episode Sonic Rainboom.

Appearances
Times stated below are approximate and taken from various videos.

First party
Heartstrings appears in the November 2011 mystery pack toys, being of the same pony kind and bearing the same cutie mark, coat color, mane color, and eye color as the unnamed character on the show. Her pose and mane style are the same as the Twilight Sparkle mystery pack toy mold. The toy comes in two variations, light teal as the toy in the picture to the right, and Irish green as the drawing on the card.

Despite only being paired coincidentally with Bon Bon on the show, the designer of the Comic Con 2011 promotional poster commented in an online forum that he intentionally placed the characters together for the poster.

Second party
WeLoveFine.com, which is licensed to sell Hasbro merchandise, carries T-shirts with the fan-made design using the character from the show, with the fan-given name Lyra.

Playful Ponies
At the 2012 Hasbro Toy Fair a Heartstings Playful Pony was reaviled as to go in the 5th "wave"

Gallery

 * Heartstrings image gallery

Trivia

 * According to a layout artist on the show, background ponies are nameless, but this pony is labeled "Incidental Unicorn #2" at the studio.
 * The lyre is a common cutie mark in the series, but it also appeared in previous My Little Pony generations, for example on the G3 Earth pony Bee Bop.
 * "Heartstrings" refers to deep feelings of love or compassion, commonly used in the phrase "tug at the heartstrings".
 * Heartstrings is seen bouncing in Friendship is Magic, Winter Wrap Up, and The Super Speedy Cider Squeezy 6000.