A long dragon boss. It features six weak spots that have to be popped using the player's attacks. It always spawns a Power Star. It uses a GeneralPos with the name プレイヤーデモ位置（ベリードラゴン戦） to position the player during the intro. If it's part of a cutscene, it also creates cutscene objects for KoopaJr and KoopaJrPod. See BellyDragonLv1Zone for a better look inside the cutscene.
| Name | Games | Required? | Description | Exclusives? |
|---|---|---|---|---|
| SW_APPEAR | SMG2 | False | The object will appear when this switch is activated. | |
| SW_DEAD | SMG2 | False | Gets activated after being defeated. | |
| SW_A | SMG2 | False | Registered but never used. |
|
| Name | Games | Required? | Description |
|---|---|---|---|
| DemoCast | SMG2 | False | Special cutscene used before the actual boss fight begins. |
| AppearPowerStar | SMG2 | True | Spawned after defeating it. |
| Camera | SMG2 | False | Used during the intro, midway cutscene and ending. |
| Message | n/a | False | The text message ID to be used. Needs to be specified in the zone's text file. The label prefix is DemoOpeningKoopaJrBellyDragon. |