This case report describes a rare instance of gemination (incomplete division) of a mandibular third molar tooth. A 30-year-old female presented with pain in her lower right back tooth region. Radiographs revealed a partially erupted tooth in the third molar region with an atypical crown and root morphology. The extracted tooth showed a single root and bulbous pulp chamber shared between two crown structures, consistent with gemination. Gemination and fusion are developmental anomalies that occur due to failed division of tooth buds. This report presents a rare case of gemination involving a mandibular third molar.