Which Mercedes-Benz concept car was modeled after the yellow boxfish?

The Mercedes-Benz concept car modeled after the yellow boxfish was the Mercedes-Benz Bionic.

DaimlerChrysler introduced the Bionic in 2005 as a research-oriented concept exploring how biological forms could inspire vehicle design. Its body was based on the yellow boxfish, Ostracion cubicus, a reef-dwelling marine species with a compact, box-like shape.

Mercedes-Benz believed the fish's form could combine low aerodynamic drag with structural rigidity. The concept reportedly achieved a drag coefficient of 0.19 and used a lightweight body, while its 1.9-liter direct-injection turbodiesel engine was paired with selective catalytic reduction to cut nitrogen-oxide emissions.

The Bionic was never a production model. It is also important not to treat its fish-inspired aerodynamics as settled science: later research questioned whether boxfish shapes are especially drag-efficient compared with more generalized fish forms. That caveat makes the Bionic notable both as an early biomimicry exercise and as a lesson in testing design assumptions.