Fanon Pokedex: Marill

Marill Line

Morphs [Oak Catalogue #]

  • Azurill [298]
  • Marill [183]
  • Azumarill [184]

Notable Bio

The Marill Line is a group of gregarious aquatic rodent Pokémon native to the watery environments of the Johto, Hoenn, and Sinnoh regions, as well as the Sevii Islands, Unova, and Kalos. The first form, Azurill, is a small Pokemon that on average stands at 0.2 meters and weighs only a mere 2 kilograms. They have two small round ears, blue-black eyes, white cheek spots reminiscent of those of the Pikachu Line and their cousins in Hoenn, Sinnoh, and Unova, and a black tail ending in a blue ball about as large as they are.

Azurill are mostly defenseless and are normally never far away from their Marill or Azumarill mothers, though they do possess a surprising amount of power for a Pokémon of their size and evolutionary level, which remains as the Pokémon evolves. An Azurill’s tail is the most important part of its body, as it uses the ball on the end for locomotion, nutrients, and as a floatation device. One Azurill was recorded as being able to hurl itself about 33 feet using its tail. This fat and oil filled tail can also be used to lessen the damage caused by extreme heat or cold. One of their most interesting quirks is the fact that they have a 3:1 ratio of females to males once hatched, which stabilizes into a 1:1 ratio once they evolve due to some of the female Azurill evolving into male Marill. (To be expanded on in Courting and Childrearing.)

Azurill evolve through having high levels of a hormone made by making bonds with other creatures. In the wild these bonds are normally made with their parents and siblings. The second form, Marill, is also a small, blue rodent Pokémon that is round in body, standing at 0.4 meters and weighing about 8.5 kilograms in the average specimen. They have large round ears and a tail just like that of its prevolution, though the ball at the end is dramatically smaller than that of an Azurill’s since the fat was eaten up during evolution.

A Marill’s fur is covered in oil that makes it water repellent, allowing them to always stay dry and conserve heat in cold water. They also use their oil-filled tails as buoys to prevent them from drowning when they go underwater in search of river grasses to eat. The reason why Marill are capable of floating is because the oil inside their tails i less dense than the water outside.

Another interesting feature of Marill is their ears, whose roundness allows them to easily catch sounds in the air. This ability allows them to very easily pick up sounds made by both other Marill and potential predators as they move through their environment, and is magnified tenfold once the Pokémon is in the water. [[Trainer’s Note: For this reason Marill and their evolved form, Azumarill, are very useful for picking up low frequency sounds.]]

After about two months in the wild, Marill will evolve into their final form, Azumarill. The average Azumarill stands at about 0.8 meters high and weighs about 28.5 kilograms. As opposed to the circular Marill, Azumarill are ovoid in shape, and have very long ears, giving them leporid as well as rodent features, and have the smallest tail ball out of all three forms. They have a lower section that is white, and a white polka dot pattern right above it, which serves as camouflage while they’re in the water.

Azumarill’s long ears give them even better hearing than that of Marill, allowing them to hear perfectly even in fast moving rivers and streams, though this also makes them far more sensitive to damage. To that end, they are always rolled up whenever the Pokémon decides to go underwater. Their ears are not only good for finding potential prey items, but also for sensing out potential predators such as Whiscash and Crawdaunt.

Another interesting trait about Azumarill is that they are very compassionate towards other creatures. If they see another Pokémon drowning, they will create pockets of air that will allow them to breathe while they are being pulled up to the surface.

Rarely, there are Azurill born with a green outer coloration and red inner ears. These evolve into Marill with the same coloration and Azumarill with a vibrant golden coloration. Even rarer is a subspecies of Marill with a complete resistance to the attacks commonly used by Grass type Pokémon. Observations of this subspecies show a markedly increased amount of vegetable consumption in the Azumarill stage, as well as a seeming increase in attack power upon being struck by any technique involving flora.


The members of the Marill Line make their homes in riverine environments. While in Johto, Marill are very rare, with the only stable population being found within Mt. Mortar, in Hoenn Marill are among some of the most common Pokémon in their waterways. Sinnoh’s Marill population is not the largest, though still larger than Mt. Mortar’s, being mainly concentrated in and around Pastoria’s Great Marsh. The Sevii Island population of Marill is fragmented, with two populations on Floe and the Ruin Valley of Fortune Island. Within Unova Marill Line members have become very common, which individuals from this line being found within Unova Routes 6, 11, 20, 22, the Floccesy Ranch, Pinwheel Forest, the Relic Path, Village Bridge, the Abundant Shrine, and Unova's Victory Road. Floccesy Ranch also appears to have a higher rate of Marill Line members of the second subtype being born within the general population. The Kalosian population of Marill is found mainly within Route 3 and Route 22.


Azurill and Marill are herbivorous, mainly living off of aquatic vegetation, though the former doesn’t eat as much due to their nutrient filled tail. They have a particular love for river grasses. Azumarill on the other hand are omnivorous with a herbivorous slant, and supplement their diet of vegetation by hunting for prey such as Krabby, Corphish, and Barboach by searching them out with their long ears.


The members of the Marill Line are rather peaceful, preferring to swim away from a potential threat. However, like most Pokemon they are capable of fighting back when threatened, or if their young are threatened. Though Azurill rely mainly on their parents for defense, if they have to defend themselves they will either blast enemies with jets of water from their underdeveloped swim bladders or slam their very large tails into them, which can necessitate a trip to the hospital.

Marill and Azurill can do the same things Azumarill can, but can also bowl over enemies by rolling into balls and charging, doing full body tackles that hurt them as well as their target, slamming them with their tails while cloaked in water, firing bigger jets of water from their swim bladders, using water to heal themselves, and summoning rainstorms in order to power up any attacks involving water.

Another danger that members of the Marill Line can have is that they may have problems controlling their own strength and may accidently end up hurting their trainer and others. For this reason it is a good idea for a trainer to properly teach their Marill how to utilize their massive strength without hurting anyone.

Courting and Childrearing

When it is time to mate, male older Marill and Azumarill compete against one another in contests of endurance in order to gain breeding rights. These contests can range from swimming races to merely who can keep a rock or Berry up longer using jets of water. After the winning male mates with the female of his choice, the female Marill or Azumarill will either lay 4-6 eggs or gestate them inside her, and the baby Azurill are born about a month later at the latest. The former process is seen most often in wild Marill and the majority of captive births, and the latter in the case of Azumarill. In captivity, a female Marill or Azumarill will lay Marill eggs instead due to the stress of having to breed outside of their natural environment. [[Trainer’s Note: If you wish to hatch an Azurill in captivity, it would be best to give the mother a Sea Incense made from the charred remnants of certain riverside herbs to remind the mother of her home environment, preventing the laying of Marill eggs instead.]]

Once the Azurill are born, they spend their first few weeks suckling from their mother’s teats until they’re old enough to eat solid food. At this point the parents take turns feeding their children while raising them in communal groups with other families, though as mentioned in Diet they don’t require a lot of food due to their nutrient-filled tail.

As mentioned in Notable Bio, the majority of Azurill are born female, but 1/3rd of the female Azurill population will become male upon evolution. The main trigger for this are certain pheromones released in the air in response to the amount of Marill and Azumarill of a certain gender around. These pheromones determine which Azurill will keep their gender and which Azurill will change their gender.

Social Structure

All members of the Marill Line are gregarious, being mainly found in groups of up to 20 individuals. The hierarchy is arranged in tiers, with the Azumarill on top and newly evolved Marill and Azurill on the bottom. The leader Azumarill are the ones who decide where the whole group goes, and are also the ones who get first pick of any particularly delicious food.

In Human Culture

All members of the Marill Line are well known for being regarded as very conventionally cute. As a result they tend to be a hit amongst young girls. Due to their ability to make air bubbles, Azumarill are often used by lifeguards when rescuing people, and their hearing makes them very useful for fishermen.

At one time it was once believed that Marill and its evolutions were closely related to Pikachu and its cousins in other regions, leading to Marill being called “Pikablu” in media descriptions. This was later disproven by genetic testing, and the Marill line was moved to a different genus.

Written by rmctagg09