Twiface refers to a series of facial expressions made by the character Twilight Sparkle in the 'My Little Pony: Friendship is Magic' episode titled 'Lesson Zero.' In the episode, Twilight becomes neurotically obsessed with finding a friendship problem to solve, leading to a mental breakdown characterized by dilated pupils, unkempt hair, and a wild, wide-eyed grin. First appearing on image boards like 4chan and Ponychan around 2011, the face quickly became a staple reaction image for expressing intense stress, hyper-fixation, or general insanity. It remains one of the most recognizable 'derpy' or 'insane' expressions in internet culture, often used to mock someone's overreaction to trivial situations.