Give some stream of consciousness and then the answer. Jim Carrey as Horton, an outgoing, eccentric, big-hearted, loving, sweet, and thoughtful elephant and teacher in the Jungle of Nool. Horton has no tusks, lives by himself and possesses acute hearing abilities. Steve Carell as Mayor Ned McDodd, the mayor of Whoville. He has 96 daughters, 1 son named JoJo and a wife named Sally. Carol Burnett as Sour Kangaroo, who mistrusts Horton's inquisitive nature as a threat to her legal authority over Nool. Will Arnett as Vlad Vladikoff, a scary, savage, eccentric Russian-accented vulture hired by the Sour Kangaroo to steal Horton's clover. Seth Rogen as Morton, a mouse and Horton's friend in the Jungle of Nool. Dan Fogler as The Councilman, a councilman dedicated to Whoville tradition and mistrustful of Mayor McDodd. Fogler also voices Yummo Wickersham, leader of the Wickersham ape tribe brothers. Isla Fisher as Dr. Mary Lou LaRue, a professor at Who U. Jonah Hill as Tommy, a bear and one of Horton's students. Amy Poehler as Sally O'Malley, Mayor McDodd's wife and mother to Jojo and her 96 daughters. Jaime Pressly as Mrs. Quilligan, a bird and Jessica's mother. Charles Osgood as The Narrator Jesse McCartney as JoJo McDodd, Mayor McDodd's quiet son. Josh Flitter as Rudy Kangaroo, Sour Kangaroo's son. Niecy Nash as Miss Yelp, Mayor McDodd's assistant. Laura Ortiz as Jessica Quilligan, a bird, Mrs. Quilligan's daughter and one of Horton's students. Joey King as Katie, a cute, but eccentric little baby yak. Bill Farmer as Willie, a bear and Tommy's dad. Heather Goldenhersh as Who Girl

Based on this passage, who played the kangaroo in horton hears a who?
To answer this question, we should know that: Carol Burnett as Sour Kangaroo, who mistrusts Horton's inquisitive nature as a threat to her legal authority over Nool.
Therefore, the answer is Carol Burnett.