A growing number of Introductory Physics for Life Sciences courses have been developed to prepare biology, premedicine, and prehealth majors for cross-disciplinary connections between physical principles and biological systems. Many students find it challenging to apply idealized algebra-based general physics to more complex biological systems. A novel biological case study was developed to teach undergraduates to expand their energy transformation analysis of a simple system--a bouncing ball--to a more complex biological system of a kangaroo hopping. Similar to a ball, kangaroos transform elastic potential energy into kinetic energy to power their "bouncing." Unlike the bouncing ball, kangaroos gain additional potential energy through metabolic processes. Students follow a sequence of guided tutorials that facilitate small-group learning as they evaluate quantitative data from video analysis with metabolic energy expenditures from literature to synthesize a real-world understanding of energy transformations. In this article, we describe learning progressions, practical tips for teaching, and lessons learned in this activity covering energy transformations.