Hmmmm craziest? There are a lot to choose from. Technically its not an insect, but I am going to go with the giant venomous centipede. The lab next to ours has one and it moves terrifyingly fast. In the wild it eats mice, lizards and even bats (@Jeff-Ha). it will attack humans, and its venom can cause liver failure. The one next door escaped and got loose in the building for almost two days. It was found again in the woman’s bathroom two floors down.
That d*mn lab looses a deadly critters at least once a month. A few weeks ago it was a whole batch of baby tarantulas. Before that it was the cyanide millipedes. Just last week it was two scorpions, which they never found.
Dancing african ghost mantises are also pretty crazy.