Here is a list of terrible but technically feasible breakfast cereals:
Muert-Os little puffed rice skulls with candy flesh coating, so when you pour milk on them the flesh melts and the red jelly inside stains the fluid with crimson.
Godzilla Crunch Shaped like little tiny Japanese people. Red jelly filling optional.
Flakes No picture on the box. You get what you pay for.
Larv-Os “The Rubbery Cereal”
Extroodles
Mini-Maggots
Sugar Sperm Make something like Prince Rupert’s Drop except out of crystallized sugar, when milk hits it the end will fragment first causing a spectacular dissolution along the length, an inevitable forward propulsion, and an unenviable metaphor. Sold with one giant marshmallow per box.