Hey, kids! Forget cops ‘n’ robbers—let’s play insurgents ‘n’ infantry! Lap Sui et al’s patent for an ultra-realistic mechanical Toy Grenade is all you need for hours of convincing fantasy maiming and menace.

Filled with a mixture of powder, dye and compressed air, the toy grenade has a functioning pin that gives a few seconds to throw, duck and cover. “Dye will spread in the air over the intended target area” like one of The Joker’s villainous props.

Unfortunately, the hemishell simply splits into two on detonation: how about a version with polystyrene shrapnel?