Day Gum is a type of gum that is chewy, (it wouldn't be called gum if it wasn't chewy) and looks like wood. The reason why it is used as a weapon by Garlic is because over time the gum hardens, making it un-chewable and the ideal weapon for Billy Bailey to use in intense combat against the Vegetables. Day gum is also stored in cylindrical containers even though they should be in a cube.