Dennis will attack the player every time they enter his room when they aren't supposed to. During the beginning of the game, Georgiger will ask the player to meet either Dennis or Johnny. If the player chooses to see Dennis, they will be greeted by him, as he questions what the player is doing in the mansion. Dennis will assume that Georgiger brought the player there, and will begin his boss fight.

In his boss fight, the player has to use the correct crusher against Dennis, depending on where he is. If you crush him 5 times, a cutscene will play where the last crusher completely wrecks him, making him lose his his right arm and his lower jaw's suiting, as well as his eyes and most of his face. Dennis will say he isn't done with the player yet, as he begins following the player throughout the mansion. Dennis will still attack the player when they re-enter his boss room, just in his damaged state.

Voice Acting this role needs you to be 13 or older and with robot effects