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 and a smile.
Mad Dummy's dialogue varies depending on how the protagonist has interacted with the Dummy in the Ruins.
- If the protagonist fled or spared the Dummy without talking to it, Mad Dummy says that the protagonist broke the Dummy's heart, who was hoping they would talk to them.
- If the protagonist talked to the Dummy, then Mad Dummy says that they said terrible things to the Dummy, spooking the ghost out of their body.
- If the protagonist punched the Dummy, Mad Dummy says that they (the protagonist) destroyed their home.
- If the protagonist bored the Dummy, Mad Dummy says that the protagonist was really boring and thus their cousin left "like any self-respecting spectre."
Regardless of how the protagonist interacted with the Dummy, Mad Dummy is enraged by it. They attack the protagonist with the intentions of stealing the protagonist's soul. The fight is later stopped by Napstablook. After the fight, they are found outside of Undyne's House taking a job as a punching bag.
True Pacifist Route
In the True Pacifist Route epilogue, the dummy remarks about the barrier being destroyed and express their apology to the protagonist for "being a dummy."
When encountering Mad Dummy in the Genocide Route, the amount of hatred directed towards the protagonist's actions allows them to "fuse with their body," fulfilling their lifelong wish. As a reward, they are willing to spare the protagonist as soon as combat begins. Unfortunately for the newly-renamed Glad Dummy, they are now vulnerable to physical attacks.
Regardless of how the protagonist has acted towards the Dummy in the Ruins, it does not affect Mad Dummy's dialogue.
If the protagonist decides to abandon the route for Glad Dummy, they can be found outside Undyne's House and continue to thank the protagonist for their corporeal form.
- For an in-battle description, see Mad Dummy/In Battle.
- The music played before the Mad Dummy fight is similar to the track "Apparent Crisis" from JoJo's Bizzare Adventure: Stardust Crusaders' soundtrack "Destination."
- It is stated that one of Napstablook's cousins also went to possess a training dummy, but it is not confirmed if either Mad Dummy or their cousin is related to Napstablook's cousin at all. In fact, after interrupting the battle, Napstablook refers to Mad Dummy as the protagonist's friend, suggesting that the two might not be related.
- Like the Dummy in the Ruins, repeatedly missing attacks/checking Glad Dummy makes them "tired of the protagonist's aimless shenanigans," and they leave.
- At the end of the fight, Mad Dummy tries to defeat the protagonist by holding their turn forever. This tactic is also used by Sans at the end of a Genocide Route, but both times the technique fails.
- The introduction scene for Mad Dummy may be a reference to the "Gutsman's Ass" scene from the Mega Man.
|Main Characters||Flowey • Toriel • Sans • Papyrus • Undyne • Alphys • Mettaton • Asgore Dreemurr • Frisk • Chara|
|Ruins Enemies||Dummy • Froggit • Whimsun • Moldsmal • Loox • Vegetoid • Migosp • Napstablook|
|Snowdin Enemies|| Snowdrake • Chilldrake • Ice Cap • Gyftrot • Doggo|
Dogamy and Dogaressa • Lesser Dog • Greater Dog • Jerry • Glyde
|Waterfall Enemies||Aaron • Moldbygg • Woshua • Temmie • Mad Dummy • Shyren|
|Hotland Enemies||Vulkin • Tsunderplane • Pyrope • Muffet • Royal Guards • So Sorry|
|CORE Enemies||Final Froggit • Whimsalot • Astigmatism • Madjick • Knight Knight|
|Amalgamates||Memoryhead • Endogeny • Reaper Bird • Lemon Bread • Snowdrake's Mother|
|Hard Mode-only enemies||Parsnik • Moldessa • Migospel|
|Vendors||Nice Cream Guy • Snowdin Shopkeeper • Gerson • Tem Shop • Bratty and Catty • Burgerpants|
|Other Characters|| NPCs • Monster Kid • Annoying Dog • River Person • Eight Humans • Asriel Dreemurr|
W. D. Gaster • Lost Souls