Mad Dummy

Mad Dummy is a ghost monster living inside a dummy located in the Garbage Dump. They also serve as a mini-boss in Waterfall. Mad Dummy takes the appearance of a dummy with a set of upper teeth on the torso, a set of eyes on the head, and nostrils on the nose. However, as Glad Dummy, they instead have two happily closed eyes, along with a smile and blush. Their overworld sprites are colored orange and red. Mad Dummy has an aloof attitude when making conclusive presumptions, which is notable when any action the protagonist does to the dummy is considered unfathomable. They also despise the feeling of powerlessness, feeling disarmed when their dummies cannot kill the protagonist quickly. They also act unhinged at exciting points of an event, often repeating three times what they say in a crescendo and uttering maniacal laughter, such as against the protagonist to entice an outward fear of hopelessness and boast their invincibility. Despite their somewhat psychotic behavior, they can be calm and collected and can cooperate with other people, seeing how they do not bother the protagonist after Napstablook interrupts the battle and serving as Undyne's punching bag for training outside her house. When Mad Dummy turns into Glad Dummy on the Genocide Route, they become so angry that they became corporeal with their dummy, making them happy and thankful to the protagonist, so if anything, Mad Dummy just needed to let off some steam.