Pfefferkorn rhymes with:
popcorn, shopkorn, terkhorn, unicorn, airborne, bighorn, bluhdorn, buckhorn, buckthorn, bullhorn, cyberporn, dearborn, einhorn, elkhorn, glyndebourne, hartshorn, hawthorn, hegadorn, hirshhorn, inborn, jetborne, kilborne, layborne, longhorn, osborn, osborne, pangborn, polkinghorn, popcorn, pronghorn, sanborn, schoellhorn, seaborne, shoehorn, shopkorn, shopworn, terkhorn, unicorn, waldhorn, waterborne, whitehorn, winterbourne