Demon Tower

Demon Tower is a Heartless that appears in Dark World and Monstropolis in Kingdom Hearts III.

Demon Towers are formed from groups of Shadows.

Kingdom Hearts III
Riku and King Mickey journey into the Dark World in search of Aqua. Though the Dark World is different to how they remember, Mickey is able to rely on his heart to lead the way to Aqua, and eventually they arrive at the Dark Margin, where Mickey is sad to realize that his trace of Aqua's light has come to an end. Before they can discuss their next move, several Shadows appear and group together to form a Demon Tower. Mickey and Riku fight and defeat the Heartless, but the Heartless reform and make a sneak attack, swallowing Riku in darkness. As he begins to lose consciousness, Riku hears someone asking if he needs help, but he is unable to identify the voice before passing out. King Mickey, meanwhile, defeats half the Shadows, prompting the rest to flee, spitting Riku out in the process.