Dictyophorus spumans, the koppie foam grasshopper or rooibaadjie, is a species of grasshopper in the family Pyrgomorphidae indigenous to Africa. The name "foaming grasshopper" derives from the insect's ability to produce a toxic foam from its thoracic glands. It is closely related to Phymateus. It grows up to a length of 80 millimetres (3.1 in). The neck shield has a warty surface, and their color is highly variable. It is toxic due to the poisons that it sequesters from its diet, which includes a large number of toxic and distasteful plants such as milkweed.