The “Big Bird” that overflew the Rio Grande Valley in January 1976 got its name from the Sesame Street character. Witnesses described it as, however, less amiable than its television counterpart. Some called it “horrible looking.” It was at least five feet tall, with wings folded around its body and large red eyes on a “gorilla-like” face. While it may have been big, it hardly seemed a bird. When Alverico Guajardo of Brownsville, Texas, encountered it on the evening of January 7, 1976, he thought it looked something like a giant bat. A week later, at R’lymondville, Armando Grimaldo heard a “sound like the flapping of batlike wings and a funny kind of whistling.” Suddenly big claws gripped his back and ripped his shirt. The assailant was a flying creature with leathery skin. It had a monkey-like face, but unlike the creature reported by Guajardo, it had no beak. Grimaldo fled under a tree, and the creature flew away. Sightings like these arose out of murky folk traditions about a large evil bird that sometimes attacks people. During the Big Bird scare theorists ascribed the sightings to various conventional causes, such as great blue herons and pelicans. There is good reason to believe that at least some reports can be so explained, though they do not fit the profile for the more exotic sightings, like Guajardo’s or Grimaldo’s.