Gracile, No Doubt

The gracile body of Procompsognathus was very much like that of Compsognathus in terms of its slender, theropod body. The long tail, as with any other theropods, was as much for balance when reaching, standing, and otherwise moving but stationary as it was for stabilization during running and maneuvering. The head was small (ish) and the teeth were built for crunching smaller insects, lizards, and mammals. Given that the legs look as though they were for running and the hands for grasping, the dinosaur was probably built to burst in speed for short distances and snatch prey on the run.