Introduction
There are many different kinds of monsters in Yugioh! with many different effects. Some monsters even have what is called an “Ability.” These monsters are Spirit monsters, Tuners, Gemini, Toon, Union, Special Summon, and Flip. One of the oldest of these Abilities is Flip, sometimes shown as FLIP. These monsters have special effects when Flipped face-up or Flip Summoned. Let’s take a closer look at these monsters!

Flip Effects
Originally, Flip was treated more like a designation than an Ability, but as more Abilities were added to the game, it was reclassified. In the early days of Yugioh!, Flip effect monsters were among the most powerful monsters in the game. Think of classic monsters like Man-Eater Bug, Fiber Jar, and Hane-Hane. Flip Monsters are designated by the word “Flip” appearing in the textbox of the card alongside the monster’s Type. The effects of these monsters are activated by Flip Summoning; being flipped face-up by a card effect, like Book of Taiyou; or flipped face-up by being attacked while in face-down defense position. While by modern day standards Flip Monsters are slow and rather weak, back in the day these cards could often change the sway of the game.
Flip Archetypes
The history of Flip Monsters is varied. At time, they were very powerful; at others, they became weak and slow. However, this has not stopped them from being printed. There are even entire archetypes dedicated to Flip Effect Monsters! The three most memorable are Subterror, Prediction Princess, and the more modern Enneacraft. Subterror is an archetype that focuses on summoning beefy, subterranean monsters with situational, but powerful effects. Examples of these cards are Subterror Behemoth Voltelluric, Subterror Behemoth Dragossuary, and Subterror Behemoth Umastryx. Prediction Princess uses Flip Monsters as part of a Ritual-focused archetypes. Their boss monsters, Prediction Princess Tarotrei and Prediction Princess Tarotreith, has an effect that allows the player to reliably flip monsters face-down or face-up, allowing you to use their effects again. Then, Enneacraft, the Pendulum archetype. This archetypes allows the players to Special Summon their monsters from their hand in face-down defense position. Other mentionable Flip archetypes, or archetypes that use Flip Monsters, are Shaddoll, Jars, Penguins, Krawler, and WAKE CUP.
Non-Flip Flip-floppers

.There are some monsters that behave like Flip monsters but are not actually Flip Monsters themselves. These monsters have effects that activate when they are flipped face-up, and they often have effects that allow you to flip them back into face-down defense position. Examples of these monsters are Flip Flop Frog, Golem Sentry, and Pharaonic Guardian Sphinx. Many of these monsters are Rock Type, as some of them are part of a strategy of taking advantage of face-down, defense position Rock monsters.
Give Flip Monsters a try in your next deck, and see for yourself how they can impact the game!