Kristen Schaal

Kristen Joy Schaal (born January 24, 1978) is an American actress, voice actress, writer, and comedian who voiced Trixie the Triceratops in the 2010 Disney/Pixar film Toy Story 3, as well as for all the shorts and specials Trixie will appear in. She also played the Anger Management group moderator in the 2011 Disney film The Muppets. She currently voices Mabel Pines on the Disney Channel animated series Gravity Falls.

Trivia

 * Her voice as Mabel is not to be confused for Vanellope von Schweetz (Sarah Silverman) in Wreck-It Ralph.