Halfsies was a breakfast cereal manufactured by Quaker Oats from 1979 through 1984. It was the result of the so-called "sugar backlash" in which the amount of sugar in children's breakfast cereals became an issue. The premise was it contained half the sugar of regular breakfast cereals, and that it was half-corn and half-rice. The cereal nuggets were shaped as half a normal cereal ring, like the letter C.
It was corn- and rice-based and, essentially, were Cap'n Crunch (another Quaker Oats product) with half the sugar and a slightly different texture.
The marketing campaign was headed by the King of The Land of Half who presided over The Land of Half. The box featured Half Land where houses, cars, food, etc. were all cut in half (i.e. only half of a house would be present with the walls open on one half and you could see into the house, etc.)
Halfsies were discontinued due to poor sales.