Moneilema gigas is a large, flightless, black beetle native to the Sonoran desert at elevations below 1500 metres. The front wings are fused forming a single, hardened shell. Collectively - with 19 other Moneilema species - M. Gigas is also known as the Cactus longhorn beetle. Like many flightless beetles, these beetles have limited wing musculature with a rounded abdomen and thorax, similar in appearance to a number of other flightless desert beetles. Cactus longhorn beetles resemble and mimic the behavior of noxious stink beetles in the genus Eleodes.