Harald Hardtooth in The Fight of the Clean Teeth is a 1992 educational DOS game designed to teach children about dental hygiene. Players guide Harald, a Viking hero, through colorful levels where he battles plaque monsters and fights to protect clean teeth. With engaging mini-games and simple controls, the game promotes brushing, flossing, and healthy habits in a fun, interactive way, making it a memorable edutainment title of the early 1990s.