Size
Size is the size of a pokémon compared to typical human dimensions. You can play with the exact height of your pokémon within these categories; for instance, a small mon might come up to your trainer's knee, or they might just come up to their shin, but they shouldn't be small enough to drop into the previous category of being able to fit into your hand.
Note that these definitions apply to both bipedal and quadrupedal mon, indicating the top of head and shoulders respectively. For noodle shaped mons (like arbok or dragonair), consider their sizing the highest they can periscope/lift the front of their body off the ground. Their actual length may be several times longer than the listed height. For hovering blob shaped mons (like solosis or koffing), consider it to be the size from bottom to top of their bodies.
You can use your reason to determine weights; please don't refer to official pokédex entries for a couple of reasons. One is that we've changed the sizes of some pokémon to fit the more monstrous or adorable appearances that some mons have, and the other is that the official entries are completely nonsensical the vast majority of the time. Look at something like an aggron - a six and a half foot human bodybuilder should weigh around 250lbs. There's no way that a seven foot beast made of
rock and steel only weighs three times that, especially when you consider that a compact car (which is hollow) weighs at least 2,500lbs! We generally advise that you just consider comparable sizes and don't worry about precision measurements anyway; if your character probably couldn't pick up a football sized lump of rock and steel, they probably couldn't pick up an aron, and so on.
Tiny
Could easily fit in the palm of your hand.
Small
The size of a domestic cat or small dog. No taller than a couple of feet.
Medium
The size of a large dog or small pony. No taller than four feet, usually average waist or chest height on a human.
Large
Up to the size of a horse and height of a human. No taller than around seven feet.
Huge
Up to the size of an elephant, at least eight feet tall but no bigger than twelve.
Ridiculous
Anything over twelve feet.
Diet
A pokémon's diet indicates what sort of food it eats! Every pokémon has to consume something, though some may consume more unusual foods than others. They have been known to eat everything from plants and meats to sunlight, electricity, even dream energy! As new diet types are discovered, they'll be noted here.
Some pokémon may have more than one food type available to them, and these will be noted as a slash! For instance, bulbasaur can photosynthesize, but it can also eat plants and meat, so it would be a phototroph/omnivore. This won't be used if a mon
can consume something but won't get much nutrition from it, such as a carnivore snacking on bread because they like the flavor. They are still carnivores for survival.
It's worth noting that pokémon consuming pokémon is not considered unusual, and human consumption of pokémon is not odd as well. Mons are this world's animals, and as such there are naturally formed food chains between them and the humans they share the space with. Generally, humans agree that pokémon with human intelligence and above should never be eaten, though there is also a strong push against advanced level mon consumption in most regions.
Phototroph
These pokémon can exist without the need to consume physical food. They absorb energy from sunlight and convert it internally in order to power their bodies, much like plants. They do need to drink water and breathe, however, so they cannot exist in a void!
Lithotroph
These pokémon gain nutrients from consuming inorganic material like rocks, metal, or soil. The preference may vary from species to species, but all of these mons convert the materials to energy using internal chemical processes. Note that this indicates a creature that gains
energy from these sources; something that nibbles on a salt lick or swallows stones for vitamins is not the same!
Herbivore
These pokémon gain nutrients from eating plants, berries, and selective plant-ish parts of other pokémon. Many of them are grazers, though some are more specialized towards more tender greens or fruits.
Omnivore
These pokémon can survive off eating both meat and plant material. Typically their internal composition leans towards a healthy intake of both, though clever nutritionists have found ways to make suitable foods made only of plants in recent years.
Carnivore
These pokémon can only survive by consuming the flesh, organs, and/or bones of other creatures. They typically require vitamins not found in plant materials to live, so vegetarian or vegan diets are not an option for them. On the plus side, most carnivores need to eat less often than others, with one large meal sustaining them for days or even weeks depending on size and activity level.
Nectarivore
These pokémon survive by consuming the nectar of flowers, with occasionally a little pollen sucked up as well. This can be from floral or pokémon sources, or even from human provided substitutes of sugary water with vitamins. This is typically a diet only had by tiny pokémon, though there have been some known exceptions.
Detritivore
These pokémon eat detritus and refuse. Most of these mons will have split diets, indicating the sorts of material they can actually consume, such as detritivore/herbivore meaning they eat rotting plant material or detritivore/carnivore indicating they typically scavenge from carcasses. These pokémon usually have no problem eating fresher varieties of these foods, so one who is a detritivore/omnivore isn't going to pass up a chance to snatch that burger off your plate! A pure detritivore is considered to be able to eat any waste/refuse, from a simple half-rotten tomato in your fridge to a pile of toxic sludge, but will also typically refuse to eat anything that
isn't detritus.
Etiavore
These pokémon are capable of eating
any of the physical food options listed. Fresh or rotten, organic or inorganic, these pokemon do not care. If they can get it in their mouth (or whatever method they use to eat), they can consume and gain energy from it.
Electrophage
These pokémon consume energy directly through the form of electricity, whether from a direct source like an outlet or from another pokémon. Some energy is lost in the process of consumption, meaning two pokémon can't just infinitely feed each other back and forth, meaning this is technically a form of predation among those with electric abilities. Most electrophages do have other options such as carnivory or herbivory, but an electrophage will
always attempt to find and consume a direct electric source before resorting to those options.
Psychephage
These pokémon are capable of feeding on the unseen energy that is inherent in all living creatures. Whether through directly sapping this life force or through other means such as devouring dreams or feasting on fear caused by nightmares, these mons tap into a direct connection to another creature's being. Psychephages have the longest time between feedings, with even the highest consumption rates having weeks between eating, but they also leave an extremely heavy impact on their victims. Prey of psychephagery is often left feeling empty, hollow, sluggish, and depressed after an attack. Sufferers of repeated attacks might find that this feeling never heals on its own, leaving some to accuse psychephages of damaging the "soul" of the victim. Owners of pure psychephages are generally encouraged to work with ranches and farms to supply suitable food that is already slated to be killed, keeping them from living with long-term effects of these attacks.
