Sarah Lynn has light brown hair with bangs that she combs over the side of her head and sea-foam green eyes. She has pale skin, freckles, and wears red lipstick. She has dark circles underneath her eyes.
In the early part of her singing career, she wore a white crop top, aqua blue skinny jeans, and open-toed purple high-heels. Later on however, and for most of the show, she has a green tattoo on her right arm and wears a button down top with skulls on one side and a purple and white pattern on the other side. She also wears shorts and yellow boots.
As a child, she had short brown hair and bangs. She wore a white tee underneath pink overalls with a pink headband.
Sarah Lynn, born Sarah Helmulfarb, was forced by her mother at age 3 to be an actress in Horsin' Around. After the show went off the air in 1996, she became a successful pop singer. At age 18, she took on a more sexualized image with the album I Am Sarah Lynn. At the height of her singing career in 2007, she had her own fragrance with Kevin Kline titled Sarah Lynn's Stank. However, her "last few albums tanked" according to her then-boyfriend Andrew Garfield, and in her late 20s she became addicted to drugs and alcohol.
Sarah Lynn looked up to BoJack off-screen as a father figure, and flashbacks indicate that Sarah Lynn's self-destructive behaviour is in part the result of BoJack (whom she idolised) neglecting and negatively influencing her as a child. At the tender age of 6, BoJack told her "The most important thing is, you've got to give the people what they want. Even if it kills you, even if it empties you out until there's nothing left to empty. No matter what happens, no matter how much it hurts, you don't top dancing, and you don't stop smiling, and you give those people what they want". The show also hints at her "photographer" stepfather abusing her as a child. Sarah Lynn was selfish and self-centered. In the episode Prickly-Muffin, she destroys BoJack's home and constantly takes advantage of him. She was often seen on her phone and was pretty irresponsible in her actions. However, she was troubled and suffered from substance abuse. It is shown that her drug addiction is a result of the loneliness that came as a result of being famous, as most of the people in her life only wanted to be around her because they wanted something out of her. She was concerned about what people thought of her. She did care about the people close to her, like BoJack.
- I Am Sarah Lynn (2003)
- Sarah Lynn is likely a parody of former child stars that later developed substance abuse problems or reputations for scandalous behavior as a result of the toxic entertainment business. Examples could include Jodi Sweetin, Mary-Kate and Ashley Olsen, Britney Spears, Lindsay Lohan, Miley Cyrus and Amanda Bynes. The Olsen twins starred in Full House (which Horsin' Around likely parodies), while Sarah Lynn's music is also strikingly similar to Britney Spears.
- She played the youngest orphan, Sabrina, on Horsin' Around.
- Sarah Lynn's stepfather was a bear. It is heavily implied that she was sexually abused in her youth by her mother's boyfriend.
- Sarah Lynn's mother emotionally neglected her as a child.
- Sarah Lynn wanted to be an architect growing up, however her mother forced her to become a child actress. She references this several times during the series.
- In the episode "Prickly-Muffin" she says she wants to be an architect but her mother criticises her for not wanting to be an actress.
- In the episode "That's Too Much Man!" she comments on the playground needing parallel joists.
- Right before her death BoJack takes her to the planetarium where she reveals she's interested in the fact the building is a dome.
- Her final words were "I wanna be an architect."
- In the episode That's Too Much Man, a painting of Sarah Lynn is shown making fun of the painting called Ophelia. The work shows a woman drowning in a lake. This could have been foreshadowing Sarah Lynn's premature death.
- Sarah Lynn's death was foreshadowed several times throughout the series.
- In Season 1, she predicts that she will die young as a result of her destructive behavior.
- In Season 1, her "Prickly Muffin" music video takes place in the same planeterium her final moments take place in.
- In Season 2, at Herb's funeral, the cast of Horsin' Around joke about which of them will die next.
- In "That's Too Much Man", Sarah makes fun of the painting "Ophelia", which depicts a woman drowning in a lake. Later in the same episode, BoJack sees that Sarah is passed out during their bender and attempts to wake her, fearing she's died.
- Sarah Lynn won an Academy Award for Best Original Song titled "The Silly Banana Song (Love Theme)" from the film, "The Nazi who played Yahtzee."
- In the season 3 finale she was on the News after having died from a drug-fueled bender with BoJack.
- She was born in 1984 and died at the age of 31.
- She overdosed on a strain of Heroin called "BoJack".