She was voiced by Tara Strong.
Claire is s typical spoiled princess, being overindulged by her wealthy father, Claire believes everything should go her way and because of that she clashes with her classmate, Lydia. Claire hates Lydia with a passion and swears to embarrass or outdo Lydia at all costs. Claire is a treacherous and narcissistic person who believes she is the prettiest, beloved and most popular girl of all the times, though it is clear nobody likes her. Claire is not only egotistical and overtly vain, she is cruel, pitiless, unapologetic, and incredibly obnoxious, so she shows no redeeming values whatsoever. She is remorseless for what she does and despite all the times Lydia and Beetlejuice (under Lydia's persuasion, of course) had saved her from danger, she still keeps her hostile personality. She is also very vapid and a total airhead who cares only about looking good and being popularity. Her personality is similar to other queen bee characters such as Angelica Pickles from Rugrats and All Grown Up, Heather Duke from Heather, Mindy from The Grim Adventures of Billy and Mandy, Darla Dimple from Cats Don't Dance, and Penelope Lang from Atomic Betty.
- Stage Fright
- Laugh of the Party
- Spooky Boo-tique
- Bizarre Bazaar
- Running Scared
- Caddy Shock
- Foreign Exchange
- Wizard of Ooze
Claire appears as "Valley Girl", she speaks with a Valley Girl accent, is seen with blonde "barbie-like" hair, has very tanned skin (though she is Caucasian) and when not wearing her school uniform, she wears a pink, girly dress.
- Claire Brewster doesn't appear in Beetlejuice (the 1988 live-action film). She does, however, appear in its animated TV series adaptation.
- She only apologizes once: to Alex, from Scandinavia, (see Foreign Exchange episode) for humiliating her in a fit of jealousy (as everyone says Alex is prettier then Claire), after experiencing what its like to be a foreign exchange student in a trip to Scrunglevania (a fake village in the Neitherworld via Lydia and Beetlejuice), but of course, she tells Alex to keep it a secret.
- Is the greatest golfer in the Peaceful Pines Country Club (obviously via distracting insults, cheating, and sheer luck), and became a golf-trophy in the Neitherworld for the Wormwood Golf Tournament. Beetlejuice only plays to win her out out of the fear she'd drive him crazy for the rest of his afterlife if she doesn't get out of the Neitherworld, even though Claire thinks the whole tournament is a dream (Lydia wins and tells the brat on return to the Outerworld that she fainted from a heatstroke, and BJ makes the lie convincing with a "Sunburn" face).
- The pranks BJ insists on pulling on her that Lydia disapproves include:
- Giving her a "swirly" (apparently)- Stage Fright, Foreign Exchange
- Scaring her head off Shakesperian style- Stage Fright
- Putting bugs (and other gross things he finds edible) in her clothing- Laugh of the Party, Stage Fright
- Delivering a slimy pizza (with "extra toppings") to her door- Laugh of the Party
- Putting her in a "first-class" electric chair- Foreign Exchange
- She is commonly mistaken as the main antagonist. However, Scuzzo the Clown is the main antagonist since Claire only makes a few appearances throughout the show. Plus, Scuzzo had bigger plans than anyone else.