Pokemon is no stranger to making Pokemon based off of inanimate objects. From icecream, keys, and sandcastles -the list is long, and often hated. More often than not these are the most criticized Pokemon. This seemingly stems from a misconception that Pokemon should be based off of animals (real or not). However, if you delve deeper into what Pokemon are based off of, it starts to make sense as to why some Pokemon are balloons, gears, and magnets too. To answer why some are based off of animals you have to ask yourself something a little deeper; what IS a Pokemon?
So, what is a Pokemon? From the outside a Pokemon is what its name implies, it is a pocket monster. What value does that hold? Not much on the surface but it does lead to cultural variations on the word. In english, a monster is defined as a, "an imaginary creature that is typically large, ugly, and frightening." <- this doesn't really sound like a Pokemon, does it? Pokemon range from big to small, cute to scary, ugly to beautiful -so would a cute and cuddly Pikachu fit this definition of a monster? It's small, cute, and not very threatening, seemingly the opposite of a monster. Another definition calls a monster, "a congenitally malformed or mutant animal or plant." and while that may fit some Pokemon like Weezing or Genesect, it doesn't fit most Pokemon as they are naturally born the way they are. So in the traditional english sense, Pokemon are not really monsters. So why are they called monsters, you ask? This is because it is going by another connotation in Japan where monster can fit the place of the word yokai. Now what is a yokai?
What are yokai, exactly? Well unlike what some may believe, yokai were not invented by Level 5's Yokai Watch series -instead they are supernatural "things" (I'll get back to why I refer to them as things in a bit) that are often translated out to as ghosts, demons, spirits, specters, etc. Basically, the west doesn't really have a word for them, so they're often translated out as to whatever they seem most like in the context of what is being translated as. Yokai themselves are usually neither good or bad but are also a bit mischiveous, much like a ghost. However, in Japan, people clearly see a difference between yokai and ghosts. Ghosts often inhabiting the nighttime whereas yokai inhabit the twilight hours of the day. Yokai themselves are hard to explain (well I mean I coooouuuullld, but I'm too lazy and want to get to the point), I'll let you see how Wikipedia describes them, "Yōkai are a class of supernatural monsters, spirits and demons in Japanese folklore. The word yōkai is made up of the kanji for "bewitching; attractive; calamity;" and "spectre; apparition; mystery; suspicious". They can also be called ayakashi, mononoke, or mamono. Yōkai range eclectically from the malevolent to the mischievous, or occasionally bring good fortune to those who encounter them. Often they possess animal features (such as the Kappa, which is similar to a turtle, or the Tengu which has wings), other times they can appear mostly human, some look like inanimate objects and others have no discernible shape. Yōkai usually have a spiritual supernatural power, with shapeshifting being one of the most common. Yōkai that have the ability to shapeshift are called obake." keep in mind what it says in one of the last lines, "...some look like inanimate objects and others have no descernible shape." which may sound similar to certain Pokemon *cough*Klefki*cough*.
Indeed, in Japanese mythology there are a lot of yokai that are based off of inanimate objects. These yokai are a subclass called tsukumogami. Umbrellas with eyes, shoes with mouths, scrolls with hands, the list of tsukumogami is practically endless. If you can think of a reason for a yokai to exist, it can take on pretty much any form you choose.
Now, that begs the question, are Pokemon yokai? No. However, they are very much influenced by the Japanese yokai. For example, Drowzee is directly inspired by the yokai the baku.
However, even though they themselves are not yokai does not mean they have not been influenced or inspired by yokai in some fashion. And in Japan, a Pokemon based off of keys or a ball makes more sense than it may have in the west where inanimate objects [typically] do not take on any life-like form. That is why some Pokemon are keys while others are dragons. From a cultural perspective, perhaps now you may appreciate them a little more, if not -at least 'get' their origins and why they exist. Just thought I'd share a brief cultural lesson with you guys :3 of course there's a lot more to cover XD but I'm not going to write all night just to educate those who may be unaware. But yeah! Hope you enjoyed :3