The Pokemon franchise is based around hundreds of imaginary creatures that all have a certain type. Whether it be Pikachu's electric type or the water, fire, and grass types that make up the starters of every mainline Pokemon game, each Pokemon has its type, which makes it more effective against some enemies in battle, and less effective against others. Water beats fire, for example; grass beats water and so on. This simple gameplay mechanic has kept fans swapping out their Pokemon for more favorable type matchups for over twenty-five years.
The types of Pokemon and the way types interact with the games has changed over time and evolved with the series. There's the introduction of new types, such as the dark type in Gen 2 and the Fairy type in Gen 6. Alongside new types, some Pokemon are given dual-types so that they gain both the benefits and weaknesses of being more than one type. There's also the regional forms of Pokemon too, which allow for some to take on entirely new types.
Considering how integral typing is to the gameplay of Pokemon, one fan has pointed out an interesting detail in how the types can work as a cycle. Creating an image to support their argument, all types except normal and dragon types can be put into a circle where the chosen type is strong against the type in front of it and weak to the type behind it. Fans of the series flocked to the Reddit post to praise the fan's realization. One comment said that the Pokemon type cycle is basically rock paper scissors with DLC.
Normal and dragon type Pokemon were left out of the cycle because as many fans pointed out these types don't follow the traditional rules. Dragon type Pokemon are weak to ice, fairy, and dragon-type moves, though the dragon type is only super effective against other dragon type Pokemon. Normal Pokemon such as Snorlax are weak to fighting Pokemon, though the normal type moves are not super effective against any kind of Pokemon currently.
Given that the Pokemon franchise is hugely popular, there are plenty of dedicated fans constantly pointing out new and interesting details within the franchise. From noticing that all the Pokemon that look like spiders don't actually have eight legs, to a detail that makes finding the wisps in Pokemon Legends: Arceus much easier, Pokemon fans are always looking for new facts about the series to share online.