Casey was a friendly, polite, somewhat shy, and obedient assistant.
Her whole demeanor changes, however, when she learns to be assertive and stands up for herself.
Casey is a human woman with long dark plum-colored hair and side bangs, and thick eyebrows. She has somewhat of a curvy build.
She wears red cat-eye glasses, a red sweater, orange skirt with flowers, a necklace, red pumps, and is sometimes seen with a red beret.
In A Little Uneven, Is All, BoJack then calls Todd, and one of Todd's assistants named Georgette answers. Todd then says BoJack is probably wondering about Georgette. BoJack says no. He then explains he can't perform his normal "Todd functions," since he became Ruthie's nanny, and stuff has been falling through the cracks.
BoJack then asks if Todd hired an assistant. Todd says assistants are like Deadpool movies. He says he couldn't just stop at one, though he probably should have and now has twelve of them. BoJack then asks in disbelief about Todd hiring twelve assistants to help him. He then talks about each of the assistants and their various assigned roles.
Todd says one of the assistants checks All About That Ace. BoJack then asks what that is. Todd then explains, it's his dating app, but as for right now he is the only user. BoJack says that makes as much sense as the rest of it.
BoJack tells him he is leaving rehab shortly, and he admits with some difficulty that he can not do this alone. Todd then says he's got BoJack's back and tells him to wait a jiffy.
BoJack is packing his things when he is startled by a woman in his room. She introduces herself as Casey and says she's an assistant, sent by Todd, to be BoJack's new best friend. Casey explains, Todd said she'd be ideal, because he could be mean to her, and he wouldn't have to feel bad—because that's what she's getting paid for. She says she is flexible and can make herself into whatever BoJack needs.
Casey then launches into a story about working for Marc Cherry. She tells BoJack about how he used to dress her in the outfit Natalie Wood drowned in and screamed at her for hours on end. She goes on to say it was very therapeutic for him. Casey also tells BoJack she didn't mind, because Marc was symbolically screaming at death, not her. BoJack says, "stars really are just like us, huh?"
Casey picks the vodka-filled water bottle and asks for a sip. BoJack stops her, and snatches it away, telling her not to drink it. She then says she must earn hydration, and apologizes. BoJack explains the bottle is filled with vodka. She asks with concern if he thinks it's a good idea, to keep vodka in rehab. She then smiles and says it is a good idea if BoJack thinks it is.
He explains it's not for drinking, he keeps it as a reminder. Casey asks what it is supposed to be a reminder of.
BoJack sadly looking at the bottle. He then tells Casey that he keeps it, because he thinks he's special and the rules don't apply to him, and he keeps thinking that repeatedly. Casey cheerily tells him that he is special. BoJack tells her he's terrible, and that all her past bosses are terrible.
He says she soothes their egos and lets them abuse her. Casey takes a step back and says she's terrible. BoJack tells her that's not his point, he then harshly tells her to have some respect for herself. She sheepishly apologizes and says she's just happy to be a part of things.
BoJack then tells her that's how they get you. He then apologizes and says it's not her fault. He then asks her to get him Funyuns, but she refuses and walks out while texting on her phone. BoJack says he likes her energy but doesn't understand what's happening. In the next scene, all of the assistants across Hollywoo leave their respective jobs. Todd's assistants also leave him, and one of them explains that the assistants are now unionizing. Todd yells that he has grown too dependent on them, and has basically become a toddler.
In The Kidney Stays in the Picture, on MSNBSea there is a news segment about meeting with industry power-brokers to negotiate terms, for a standard agreement. Stuart and Casey McGarry are seen on the news. Casey is being interviewed about the HGA negotiations. She says she is optimistic about the coming talks and confident they can avoid a strike. She goes on to say their demands are reasonable, and their services are crucial to the industry.
Casey, Stuart, and some other assistants are seen in a conference room with Lenny Turteltaub. He tells them he wants to wrap it up quickly and then asks what they want. Casey says they have one request, to not be treated like garbage. The other assistants all nod in agreement. Lenny then says they are at an impasse.
With the assistants on strike, the whole city is shut down and everyone is in a panic.
Casey is meeting with Lenny and Princess Carolyn. Casey tells them she doesn't feel comfortable negotiating without her fellow assistants. Lenny tells her this is not about that. Casey says their demands haven't changed, and Princess Carolyn says she finds it thrilling to see her grown into her role as strike captain. Lenny then tells her there is an opening in his company for a development executive. He asks if she'd be interested.
Casey says she's never really thought about it and would have to think about it. Lenny tells her she would get overpaid to read scripts, a company credit card, and a parking spot in the good garage, plus her own assistant. Princess Carolyn says, that is, of course, if the strike ends. Casey says it's a generous offer but she'd have to talk it over with her colleagues.
Princess Carolyn asks "Why? Those are assistants. You're not one of them anymore, you're one of us." Lenny slides the contract to her, telling her it's a two-year contract, and once she signs her troubles will be over. Casey signs the contract. As Princess Carolyn shows Casey the door, she reassures her she's made the right decision and she'll love the new job. Lenny calls her Stacey and welcomes her to the team. She tries to correct him, and Princess Carolyn slams the door on her face.
- An interview on the news shows her surname is McGarry, in The Kidney Stays in the Picture.