antagonist (n.)
- actor
- actress
- adversary
- anti
- antihero
- assailant
- barnstormer
- bit
- cast
- character
- combatant
- competition
- competitor
- con
- contender
- cue
- devil
- enemy
- feeder
- foe
- foeman
- foil
- heavy
- hero
- heroine
- histrion
- ingenue
- juvenile
- lead
- match
- mime
- mimer
- mimic
- monologist
- mummer
- opponent
- opposer
- opposition
- pantomime
- pantomimist
- part
- person
- personage
- piece
- playactor
- player
- protagonist
- reciter
- role
- side
- soubrette
- stooge
- stroller
- theatrical
- thespian
- trouper
- villain
- walk-on
He that wrestles with us strengthens our nerves and sharpens our skill. Our antagonist is our helper.