The Snort Laugher (gigglius hoggii)

This species of commuter tends to travel in packs. Almost always female, young and upwardly mobile with a high quality knock-off bag and shoes she probably can't really afford but purchased anyway for the street cred.  Snort laughers generally inhabit 3/3 combo rows so they can pretend to admire each other while secretly committing fashion faux pas and personal drama to memory to be used as arguments starters at a later date.  These unpleasant creatures are known for recounting old Seinfeld episodes and snort laughing at maximum decibel levels.  This behavior can also be accompanied by extended cell phone use, excessive complaining about ticket prices, and inappropriate flirting with male conductors.  Packs of snort laughers are to be avoided at all costs, it is highly recommended to switch cars at the first viable opportunity if you find yourself unexpectedly in their presence.