Kellogg’s Frosted Flakes is a breakfast cereal, produced by the Kellogg Company and consisting of sugar-coated corn flakes. It was introduced in the United States in 1951, as Sugar Frosted Flakes. The word “sugar” was dropped from the name in the 1980s.

Tony the Tiger has been the mascot of Frosted Flakes since its introduction. Tony is known for uttering the cereal’s slogan: “They’re Gr-r-reat!” (pronounced as one elongated word, not a stutter). Tony the Tiger was originally voiced by Dallas McKennon, but Thurl Ravenscroft voiced him for more than 50 years, until his death in 2005. Tony is currently voiced (in Canada and the US) by former professional play-by-play announcer Jim Van Horne.  Van Horne also voiced Tony in a 1997 television commercial. In the UK, Tom Hill voiced Tony after Ravenscroft’s death. Tony is drawn wearing a red scarf on all Frosted Flakes cereal boxes.

Another character, Katy the Kangaroo, was on the Frosted Flakes box for a short time.

Info gleaned from Wikipedia