Martlet is a major character of Undertale Yellow, the boss of Snowdin, the second major area of the game, the tritagonist of the Neutral and Pacifist Routes, and the final boss/main antagonist of the Genocide Route. Martlet is shown to be, as the game states, scatterbrained, and kinda lazy. She is a member of the Royal Guard. While she seems a bit naive on the surface, what Martlet makes up for in her disorganized workflow is her strong morale. Bernardo's friend.