ped/pod = foot
biped (n) a creature with two feet
centipede (n) a creature with 100 feet
impediment (n) something that stands in one’s way; an obstacle
millipede (n) a creature with 1,000 feet
pedal (n) a lever that is moved with one’s foot
peddler (n) a person who goes from door to door on foot trying to sell a product
pedestrian (n) a person who walks across the street on foot
pedicure (n) a foot treatment that could include soaking the feet and polishing the toenails
quadruped (n) a four-footed creature
tripod (n) a three-footed stand often used to balance a camera