Stomach contents dataset (raw data) used for the manuscript entitled "Biological invasion of a semi-aquatic vertebrate involves wide-scale predation across the water-land interface of ponds" and authored by Fabien Pille, Laura Pinto and Mathieu Denoël from the Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), University of Liège, Liège, Belgium