|Boss of Dark Shadow|
Rainbow Islands Revolution sprite
|First appearance||Rainbow Islands|
|Species||Bubble Dragon (First form)|
Skeletal Beluga (Second form)
|Alternate form of||Baron von Blubba|
|Alternate names||Super Baron von Blubba|
Dark Demon King
Boss of Shadow
The Boss of Dark Shadow is shown to be able to shoot bubbles, much like other Bubble Dragons. Its bubbles can transform humans into Bubble Dragons. Its second form, the giant Baron von Blubba, can shoot winged versions of the Baron out to attack its foes.
The Boss of Dark Shadow is the final boss and main antagonist of Rainbow Islands. It is fought in the last world, Bubble Island. As Bubby and Bobby enter the room, the Boss awakens from its slumber and moves around the room, shooting bubbles at Bubby and Bobby. After being hit enough times, the Boss transforms into a giant Baron von Blubba. Von Blubba moves around the room, trying to hit Bubby and Bobby.
In the Game Boy Color version, the Baron can shoot winged versions of himself at the two. After being defeated, the Baron taunts Bubby and Bobby, and the room fills with his blood. The two must jump on platforms to escape the blood, which will make them lose all their lives if it touches them.
Although Baron von Blubba perished in Rainbow Islands, the Boss of Dark Shadow returns as the boss of Rainbow World. This is thought to be due to Chaostikhan's magic, and not the real Boss of Dark Shadow. It acts similar to his first appearance, although Bubby must defeat it using Water Bubbles. The Baron von Blubba form does not appear in this game.
The Boss of Dark Shadow returns in Rainbow Islands Revolution, once again acting as the final boss. Dark Shadow acts extremely similar to its first appearance, although he is not fought the same way. Bubby, Bobby, Mike, and Violet must draw rainbows using the DS touch screen to attack the Boss.
- The Boss of Dark Shadow is referenced in Bubble Memories by way of the game's main antagonist, the Super Dark Great Dragon, as both are large armored Bubble Dragons with wings. The Super Dark Great Dragon is actually referred to as the "Dark Demon King" (Dark Shadow's Japanese name) in the Japanese story of the game, and was referenced as initially appearing to be the entity defeated in Rainbow Islands, but it is unknown whether or not the two are intended to be the same character.
- The similarity between the two characters was referenced in the ending of Bubble Memories, which states that "History repeats itself...", referring to the similar events of the two games.
- The Boss of Dark Shadow is one of three Bubble Dragons with wings, the other two being the Super Dark Great Dragon and Develon.
- Upon defeating Super Baron von Blubba in Rainbow Islands, he exclaims "What strength!! But don't forget there are many monsters like me all over the world". This quote appears to be a reference to the victory text in the original Street Fighter, which was released just barely over a month before Rainbow Islands, in which the player's opponent states "What strength!! But don't forget there are guys like you all over the world" after being defeated.