Locusts are large insectoid creatures, about the size of a housecat, looking something like the cross between a stag beetle and a housefly. They have a bluish, iridescent shell, long, pincerlike mandibles, wings, and multifaceted eyes which allow them to see in all directions at once.
They have an incredibly high metabolism, and feed ravenously on anything organic they run across. When satiated, they slip into a hibernation period, falling practically wherever they happen to have been at the time. In this state, they are largely unaware of their surroundings, and can even be picked up and handled. But if there is a loud noise, they spring to life and start eating. (Note that “eating” includes attacking humanoid characters for their flesh.)
This behavior emerged as an adaptation to life here in Verdant. The natural cycle for Locusts, unless disturbed, is to be awakened seasonally by thunderstorms. They awaken, eat voraciously until the rains make it difficult for them to fly, and they curl up and hibernate again.