Lacertimorphism

Lacertimorphism is the ability of a species to significantly alter their musclature, often as a temporary measure for self-defence. Large muscles provide greater power, but are incredibly energy-inefficient, resulting in a bilateral metamorphic adaptation to switch between low-energy, low-musclature forms and powerful but inefficient forms. There are several Lacertimorphic species in Universalis Primus, most notably the Giss.