ON Madison Avenue, there are talking dogs, talking horses, even talking margarine tubs, not to mention talking brand characters like the E*Trade babies and the Keebler elves. But Mr. Peanut, the dapper Planters mascot since 1916, has never spoken  until now.

Mr. Peanut is getting a voice as part of efforts by the Planters parent, Kraft Foods, to revitalize the character, and the brand, for contemporary consumers. The voice is being supplied by the actor Robert Downey Jr. in an animated commercial that is to be introduced on Tuesday.

In another sign of how keen Kraft is to update Mr. Peanut, the commercial is to be previewed on the character’s Facebook page (facebook.com/mrpeanut) before it runs on TV and in movie theaters.

The humorous commercial will also unveil a new look for Mr. Peanut, meant to give him a more authentic appearance by evoking designs of the character that date to the 1930s and 1940s. He is now brown, rather than yellow, and sports  appropriately for a spokes-character  a gray flannel suit.