Filo (フィーロ, Fīro?) is a Filolial purchased alongside Raphtalia during the outset of the story who develops into a Filolial Queen due to her association with the Shield Hero and she is a staunch ally to the hero, as the possessor of unique class-up effects. She also becomes particularly close to the Second Princess Melty Q Melromarc.
Filo's appearance has changed many times, depending on her form.
When Filo was born, she was a small, pink chick who looked to be about the size of an average chick. After a day, and some leveling, she had grown to the size of a steamed bun. Filo's third appearance change would be to that of a small, baby ostrich, not quite large enough to ride on, but definitely larger than her two prior forms. Filo would then grow into her fourth beast transformation, which was the size of a normal ostrich, and she was now capable of being ridden. It should also be noted that Filo's feathers had started to turn into a much lighter shade of pink than in her prior forms, and were beginning to turn white. Filo's last and most current form is larger than an ostrich and resembles an owl. Her feathers are also almost completely white aside from a small ruffle on her abdomen and some feathers on her wings, which still contain pink.
Filo can change to her human form, which takes the appearance of a young girl with wings on her back. She wears a white dress with a blue bow on the center made out of magical crystal threads so they don't break when she transforms into her beast form. She also always goes barefoot.
Her eyes in both forms are blue. Filo later gains a cowlick (a third long feather in her Filolial Form) that sticks vertically out of her head, which serves as a symbol of Filo's succession from the Filolial Queen, Fitoria.
Filo's personality has varied greatly throughout the story. Filo originally acted like any normal animal, prior to her transformation ability as she ate a lot, showed a great amount of affection towards Naofumi Iwatani and even convinced Naofumi to sleep in a stable with her because she was lonely by pulling on his mantle.
After Filo gains the ability to transform, her personality becomes that of a spoiled child; she refuses orders until she is fed, throws fits when Naofumi doesn't sleep in the same bed as her, and will randomly transform whenever she sees fit. In an attempt to try and fix her personality, Naofumi threatens to sell her (and with a little help from an advanced slave mark), after which Filo begins to behave much more appropriately. Since that point, Filo has become a trustworthy and reliable member of Naofumi's party. Filo works hard to gain Naofumi's approval so that she won't be pushed aside if something should happen to her (though it is unlikely Naofumi will really ever do that and instead uses it as a threat to discipline her).
Filo is also known to be very caring who has shown great affection towards Melty Q Melromarc, the second princess of Melromarc.
Although she is comparatively smart to others of her own kind, she is mostly an airhead and doesn't pay much attention to anything that she has no interest in. She will often doze off when others are talking about things she has no interest in. Initially, She has a poor understanding of behavior, culture and common sense.
Filo also loves to swim and can go underwater and hold her breath for hours. Since she is a bird, she collects shiny objects as her treasure, though they really are just trash. She enjoys singing and learns a song in every tavern the group visits by watching the regular patrons before joining them. Filo cares for children and plays with them whenever she comes across them. She also sings a lullaby for the new slaves of Rock Valley village to make them sleep comfortably. She also tries to lift the spirit of the news slaves to relieve them of their past trauma.
Filo has a boundless appetite and has poor table manners, which contradicts her appearance. She eats everything and anything. She even once remarks that she thinks that her own kind looks delicious and is even willing to eat a rotten dragon corpse. However, she hates alcohol and rucolu fruit. Nafoumi uses this monstrous appetite to threaten his enemies, that he may feed them to her. Filo also joins Nafoumi's play, much to their horror. Though this trait changes in course of time.
Filo is way too talkative and most of her conversations don't make any sense. Melty is the only person to understand Filo's words. Filo can figure out and say exactly the things people are trying to hide. Her bluntness is mostly due to her naïve personality, which sometimes deepens the other person's wounds. or exposes their intention infront of everyone.
Filo has a strange way of associating others with items rather than remembering by names like addressing:
- Motoyasu Kitamura as Spear
- Itsuki Kawasumi as Bow
- Ren Amaki as Sword
- Eclair Seaetto as Red Veggie
- Ost as Turtle lady
- Glass as Fan lady or a see-through person
- Therese as sparkle person
- L'Arc Berg as Scythe
- Kizuna as a fishing lady
Although there is no ill intent and is her way of remembering them, many find it to be hurtful for being remembered as anything other than their name. One time, she referred to Imya as a delicious looking kid, which became a horror for the new slave kids.
Filo is a good judge of character and is able to see through anyone, which is shown many times such as when she refuses to let Raphtalia have Naofumi (knowing Raphtalia's feelings for him), Naofumi's strange or rude thoughts, Motoyasu's intention and Itsuki's personality. This also includes the lies and evil intentions of people like Mald, Malty S Melromarc and Jaralis. It is this trait of Filo that convinces Naofumi to trust Melty as Filo completely trusts her. She’s been reserved as of late, but from the start, she’s been overly intrusive. She can see through lies and has exposed many. Naofumi uses her to verify the credibility of the truth told by people.
After spending time with Melty, she displays more fitting behavior and has corrected most of her flaws. She also learns many social and cultural behavior from Melty. At times, she is clearly disturbed by Naofumi's threatening of bandits about using her to eat them. She was horrified and disgusted by Jaralis grotesquely monster transformation and also him cannibalizing his own allies. This was not the case earlier. Her personality matures, but she still retains many childish traits.
If nothing else, Filo completely lives and relies on her instinct, which is absolute according to Naofumi.
Once, Filo overheard the slave merchant talking about her and that the filolial egg that he sold to Naofumi was a cheap one. The egg was from two flightless birds that was meant to be raised for the meat. The egg was worth 50 pieces of silver, the same price as the adult species.
Her fate changed when Naofumi picked her egg and raised it.
- According to Naofumi Iwatani, Filo is interested only in food, carts and Melty Q Melromarc.
- In nature, Filo like all her own kind hates dragons.
- Filo's egg was purchased for 100 silvers where her advanced monster crest was 200 pieces of silver and 40 pieces of silver for her clothes, making it a 340 silver pieces as her initial investment.
- The Slave Trader is willing to purchase Filo for 30 gold coins.
- Like all Filolials, Filo likes pulling carts. If a Filolial isn't allowed to pull a cart from time to time, they become restless.
- In the anime, Filo (in her Filolial form) hasn't grown her third antenna feather after receiving her Queen succession from Fitoria.
- Filo has a soft spot for Naofumi as shown when she protects him from the Filolial Queen.
- It is implied that Sakura is an alternate version of Filo, but since the conditions that lead to her acquisition and hatching were different, she hatches differently in Reprise.