Although answer set programming has been a tried way of problem-solving for over thirty years, few tools and methodologies exist today to test it rigorously. Previous research suggests that mutation testing is able to uncover flaws even with small inputs. In this paper, we introduce clingabomino, a mutant generator implemented in C++ that directly operates on the abstract syntax tree of the Clingo solver. Our tool consists of a command-line application that implements commonly useful mutation operators as well as a library to aid in the development of domain-specific mutation operators.