Cereal Killer Halloween costume. For more details see the article 15 Creative Solo Halloween Costume Ideas For Every Party 80+ Best Halloween Costume Ideas To Become The Best Dressed This Year Funny Cereal Killer Costume Cereal Killer Costume Cereal Killer. If you love to smash down some cereal then this outfit is perfect for you! This adults novelty cereal killer fancy dress costume will make you look hilarious this Halloween. Become a cereal killer in this funny men's Halloween costume. Costume includes a black stretch fabric vest with velcro closure at the back. Cereal Killer details are printed on the polyfoam front of the vest. Does not include T shirt, pants or knife. One Size Fits Most