A familiar advertising spokescharacter who began talking only two and a half years ago is speaking with a new voice.

The mascot is Mr. Peanut, the symbol of the Planters brand since 1916. In a campaign for a new product line, Planters Nut-rition Sustaining Energy Mix, the comedian Bill Hader takes over as the voice of Mr. Peanut, succeeding the actor Robert Downey Jr.

Mr. Downey’s arrival in November 2010 was part of an effort by the Planters parent, Kraft Foods, to revitalize Mr. Peanut -- and the Planters brand -- for contemporary consumers. The makeover also included a new look for the character, meant to recall his roots, and a new theme for Planters ad campaigns, “Naturally remarkable.”

Now, Mr. Downey is moving on as his contract ends, in a departure that executives at Kraft Foods and the Planters agency, Being New York, call amicable. Mr. Downey continues to supply the narration for commercials for Nissan North America and, according to reports, has agreed to appear in coming ads for HTC smartphones.