Rich mathematical modeling activities are crucial to giving students agency and making mathematics meaningful. Proportional reasoning and transitional algebraic reasoning are the primary topics in the prealgebra curriculum, so a need exists for meaningful modeling activities using proportional reasoning in addition to geometric modeling. In particular, there is a need for informal algebra activities to help students see the uses of algebra in real-world contexts. This article describes a modeling activity based on the popular Pokémon Go game. First-year algebra students used their knowledge of mathematical modeling and rates to decide on the best possible buddy, discovering two models independently and a third, combined model in whole-class discussions. The article provides suggestions for how teachers can develop their own authentic modeling tasks that would be relevant for their students.