|“||I'm really happy you found this speck...but you might wanna keep it to yourself.||„|
|~ Morton to Horton|
Morton the Mouse (or just Morton) is Horton's best friend and a major character in the 2008 animated film Horton Hears a Who!. He is voiced by Seth Rogen, who later voiced B.O.B. in Monsters vs. Aliens and Mantis in the Kung Fu Panda franchise.
Morton is shown to be level headed and loyal as he tries to encourage Horton to keep the clover carrying the speck with Whoville to himself, but when he asks Horton to rid himself of it, he reluctantly agrees to Horton's dedication to keep it safe and when the animals begin to believe Kangaroo's story of Horton bringing anarchy to the jungle, Morton is the only animal who doubts it an runs to warn Horton about the mob.
- Morton is not from the original book. He was named after "Morton the Elephant Bird" in the other book Horton Hatches the Egg.