The Fan is an enemy faced in Carltron's Lair as part of the final boss battle.
The player must destroy the Fans and the Speakers to advance to the next stage of the battle. They have no damaging attack, but can blast wind and sound at the player to drive them back across the room, potentially into the path of Bombs. Otherwise they are defenseless and the player should have no trouble destroying them.
The player gets no rewards for destroying the fans.