Trouble Bruin is a puppet who appears as the main antagonist in the game Dynamite Headdy.
The character underwent a significant change from its original Japanese form to what was eventually seen by Western audiences. The character was originally named Maruyama, and appeared as a hired assassin whose job it was to eliminate Headdy. In the games Western translation, the Maruyama moniker was switched to that of "Trouble Bruin". The change was not only in name, but also cosmetically. The sprite was modified significantly, the original bright purple mascot, with it's wide staring eyes was changed to a more subdued brown version, which wore a permanent frown. His role as an assassin was also dropped, instead becoming a jealous rival of Headdy.
Trouble Bruin was just one of many art style changes within the game. These modifications largely entailed the scaling back on many of the Japanese overtones of various bosses. Here, the changes were likely done to highlight the fact that the character is a bear. However, even with these changes, many players still often mistake Bruin as a Cat.
Bruin occasionally appears to face Headdy, he is the only boss character to re-appear multiple times throughout the game.
In each of these boss battles, Bruin attaches his head to a new device in a bid to thwart the players progress, the stages vary wildly, as does Bruin's appearance.
He also appears in the background of multiple stages, often having an indirect effect on the action, such as dragging Headdy into the following level. The regularity of his appearances is referenced in the stage "Mad Dog", here Bruin appears ready to fight Headdy only to be crushed by the real boss. During the proceeding battle, he can still be seen on the underside of the Mad Dog boss itself!
The character has a reoccurring theme known as "Maruyama appears", it is present in all versions of the game. However, considering the context of the changes that were made for Western players, the song makes little sense as the original moniker of Maruyama can still clearly be heard as lyrics.