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