Limbless vertebrates display a variety of morphologies, which are often linked to a species’ ecology and locomotion. Pygopodids, limbless gekkotans endemic to the Australo-Papuan region, exemplify a spectrum of ecomorphological variation in relative body-to-tail lengths. Delma molleri inhabits grasslands and represents the short-bodied and long-tailed ecomorph. We predicted that its locomotor performance would be enhanced on grass substrates as opposed to structurally simpler substrates. To test this hypothesis, we assessed locomotion of D. molleri through three ecologically relevant substrates. Locomotor performance was significantly faster on the grass substrate over multiple distances. These data provide evidence of a functional performance benefit for limbless lizards with short bodies and long tails in grassy habitats, supports theories that such a morphology may have evolved to suit the occupation of these environments, and provide the first evidence of the functional benefit of long tails for locomotion through grass in a member of the Pygopodidae.