Chicken Little is a character from the fable of the same name. Her only appearance was in the Shrek 2PC game on a wanted poster, where she is wanted for inciting civil unrest. This references her attempts to tell her farm community that the sky was falling and causing mass panic. She is also the subject of a clever pun on the same poster.
She did however get mentioned in the "Shrek" YouTube series "Swamp Talk". Although she was referred to as a "he" despite having "chicken" in the name. Donkey mentions how the chicken is "angry" by yelling "The sky is falling!" to everybody. Shrek tells him that Chicken Little isn't really angry, but misinformed and scared.