Abstract — With increasing sensing, motion, and processing capabilities, robots start to master more and more complex tasks in difficult applications. Especially working in hazardous environments, such as exploring extraterrestrial planets or nuclear disaster sites, demand robotic solutions with advanced locomotion capabilities in unstructured terrain. Four-legged systems can provide the desired mobility. The hominid robot Charlie has, in contrast to most quadrupeds, an active ankle joint with Multi-Contact-Point-Feet to support four-legged as well as two-legged locomotion. In this paper, the advantages of this foot design for four-legged locomotion is analyzed. The paper summarizes briefly Charlie's hardware and software components. In detail, the foot design and the behavior modules which utilize the possibilities of actively controlled Multi-Contact-Point-Feet are described. The experimental results show that a positive effect on traction and range of motion are achieved which improve the mobility of quadrupeds.