In this paper, we present Pegasus Transforming UAV/UGV Hybrid Vehicle, a unique, transformable UAS/UGV that is particularly well-suited for missions. The combination of flight and ground modalities allows Pegasus to fly to location, automatically transform into a ground vehicle, reposition, and quietly approach a target; or, Pegasus can land and “perch” for long durations, allowing for the maintenance of the custody trail and long ISR missions or emplace sensors particular for a specific mission. The sequential use of aerial and ground capabilities in this platform provides the reach usually lacking in these missions. The Pegasus platform was developed with DTRA/ARDEC funding in support of specialized missions where these functionalities are needed. Robotic Research, LLC has developed the system from the ground up, including: mechanical, electrical, and software designs (without using foreign-made parts). The current system is shown in Figure 2. The system already has obstacle avoidance payloads, and has demonstrated capabilities in GPS-denied environments and SubT, while mapping and traversing line-of-sight and NLOS areas.