Various characters appeared in the sitcom "Friends", which aired for ten seasons on NBC from 1994 to 2004. It featured six main cast members: Rachel Green (Jennifer Aniston), Monica Geller (Courteney Cox), Phoebe Buffay (Lisa Kudrow), Joey Tribbiani (Matt LeBlanc), Chandler Bing (Matthew Perry), and Ross Geller (David Schwimmer). Many celebrities guest starred on the series throughout its ten-year run.

Ursula Pamela Buffay (Lisa Kudrow): Phoebe's identical twin. Kudrow originated the role of Ursula in the sitcom "Mad About You", playing her as an inept waitress at Riff's who frequently forgets orders. Ursula is every bit as odd as Phoebe is, but, unlike her sister, Ursula is a selfish, amoral, abrasive, brazen and hedonistic individual who is so self-absorbed and self-centered that she often forgets things, usually treats Phoebe with disdain and is not liked by anyone who truly knows her. Phoebe refers to Ursula as her "evil twin."

She first appears in "Friends" in "The One with Two Parts": Chandler and Joey are eating at Riff's and mistake Ursula for Phoebe. Joey becomes attracted to Ursula and they start dating. Ursula tells Phoebe that she is bored with Joey and sarcastically claims that he is smart enough to figure this out on his own without her having to actually tell him (implying his stupidity irritated her, hence her naturally nasty reaction), so Phoebe pretends to be her sister to let Joey down gently.

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