Nellie Bertram

Nellie Bertram is a fictional character on the U.S. comedy television series "The Office", played by Catherine Tate. She first appears as a guest star in the seventh season, where she interviewed for the Regional Manager job at the Dunder Mifflin Scranton branch. 
She is an original character, and was not copied in the original British version of the series.
She was reportedly the top choice to replace Steve Carell, but was unable to join the series, due to her other work at the West End production of the Shakespeare play "Much Ado About Nothing". 
However, Tate later returned to the role as a series regular for the second half of season eight and continued in the role for the final season.