Final answer:
The fibularis longus muscle has a tendon that loops around the lateral malleolus and is responsible for plantar flexion and eversion of the foot.
Step-by-step explanation:
The muscle that has a tendon that loops around the lateral malleolus is the fibularis longus (also known as peroneus longus) muscle. This muscle is located in the lateral compartment of the leg. Its main functions are to plantar flex the foot at the ankle and evert it at the intertarsal joints.