MINNEAPOLIS—General Mills, maker of the popular breakfast cereal Lucky Charms, announced Tuesday that the morning favorite will soon become much more lucky with the addition of 16 new colorful marshmallow shapes, displacing the unpopular oat pieces that have hampered the cereal's appeal for decades.

Lucky Charms, a nutritious part of a complete breakfast, will soon contain nothing but marshmallow pieces. As General Mills' vice-president of product development John Stacey explained, "Why put off the inevitable?"

"We've been moving toward total marshmallow saturation for quite some time now, upping the marshmallow-to-oat piece ratio through the gradual introduction of 'new' marshmallow shapes," said General Mills vice-president of product development John Stacey. "We just finally said to ourselves, 'Why put off the inevitable?'"

In addition to the already-existing marshmallows in the shape of hearts, stars, moons, clovers, horseshoes, balloons, rainbows, and pots o' gold, every box of Lucky Charms will now feature 16 brand-new shapes: clubs, spades, treasure chests, crowns, sevens, bells, planets, coins, suns, smiles, clouds, boats, lightning, comets, anchors and rings.

"The monochromatic oat pieces in unrecognizable shapes were by far the least popular part of Lucky Charms," said Terrence Sweeney of Scarsdale & Loeb Group, the marketing firm handling the change-over. "Although when eaten alone, the lightly frosted, tan-hued oat pieces are quite delicious, when eaten alongside the explosively sweet marshmallows they seem stale and cardboard-like."

The ad campaign for the revamped cereal begins next month with a television commercial featuring "Evil Oaties" gobbling up all the marshmallows in Lucky Charms. After a bit of leprechaun magic from "Lucky," the Oaties transform into the brand new marshmallow shapes before the eyes of delighted children.

"We're already thrilled with the response to the new cereal," Sweeney said. "The children in our focus groups responded very enthusiastically to the new Lucky Charms. In fact, they immediately asked for more of it, often clinging to the legs of our testers until they received second and third helpings."

Said Lucky Charms fan Timothy Nordquist, 5, after eating a bowl of the new cereal: "Nur nur nur nur nur nur nur nur nur nur nur."