Graphs are well-studied mathematical structures that have diverse applications in fields such as computer science, chemistry, biology, and social sciences. In this respect, graph rewriting is a powerful technique that allows for the manipulation of graph structures through the application of so-called graph transformation rules. In other words, graph rewriting techniques elevate static graphs to the concept of time-varying graphs. BiGGer is a Java library that implements a novel approach to graph rewriting for bigraphs, as devised by Robin Milner (Milner, 2009), using the graph transformation tool GrGen.NET (Geiß et al., 2006). Bigraphs provide a compositional framework to model graph structures with two semantic dimensions that can be reconfigured by rules. With regard to BiGGer, bigraphs are specified using a meta-modeling approach (Grzelak, 2023; Kehrer et al., 2016) that is based on the EMOF standard (ISO/IEC 19508:2014, 2014), which is common in the software engineering sciences, where this library is most useful. Grounding bigraphs on metamodels facilitate its construction via a universal and platform-agnostic language. Ultimately, this library transforms EMOF-complaint bigraphs into multigraphs that GrGen.NET can visualize and execute. Furthermore, BiGGer is also shipped as a command-line tool for using the functionality via the terminal for experimentation. The most challenging aspect was the accurate translation of bigraphical rules to SPO-based rules, given that bigraphs and GrGen.NET employ distinct approaches regarding graph rewriting.