Pico de gallo!

Have you been eating a tomato-onion-and-cilatro-based Mexican salsa all your life and never bothered to wonder why it has the name it does?  Well then you are in for a treat!  Translated in Spanish, pico de gallo literally means "beak of rooster."  What's that got to do with the salsa?  Well, its etymology is uncertain.  Some believe this is because it was originally eaten by pinching between the thumb and finger, making the shape of a rooster's beak. 

Citation needed: Here are some other theories that Wikipedia has to offer:

• In their book Authentic Mexican: Regional Cooking from the Heart of Mexico, Rick Bayless and Deann Groen speculate that the name might allude to the bird feed-ike texture and appearance of the mince.  (That doesn't sound very likely to me, and anyhoo, where would the beak come in?)
  
• Many native residents of the Sonoran Mexico region explain that the salsa is thus named because the serrano pepper resembles a rooster's beak in shape.
• According to natives of California's central valley, it is believed that the term originated from the rooster’s beak. Roosters, who are known to peck noodles off of unsuspecting children's faces, have a fierce temperament. The fiery "bite" of the rooster is supposedly akin to the spiciness of the pico de gallo.  (Hmm, then why wouldn't it be called "peck of the rooster"?)
  

Because the colors of the red tomato, white onion, and green chili and cilantro are reminiscent of the colors of the Mexican flag, it is also called salsa bandera ('flag sauce').