At 15 months (1 year and 3 months) old, Lily is the youngest child of the Loud family, and the youngest of Lincoln's five younger sisters. She is able to walk independently, and is learning to speak. She has a tendency to poop in her diapers, leaving a foul stench known to disgust her older siblings, and often removes her diaper, forcing her siblings to constantly have to put it back on. Lily has a habit of crying. Lincoln always changes Lily's diaper in Lisa & Lily's room.
Lily is always happy, and enjoys being with her siblings. Unlike other babies, she doesn't cry too often. She is also the most behaved of the siblings.
Even though she's just a baby, Lily is shown to be fairly aware of her surroundings, and especially of her siblings' many antics, in which she is often swept up. In "Undie Pressure", she intentionally sucks on her pacifier to stop herself from crying, and ends up winning the challenge for her family. She becomes angry at Lincoln for posting their sisters' embarrassing moments online in "Making the Case", despite that she wasn't filmed, and helps her sisters Lola, Lucy, Lori, and Leni convince Lincoln to choose Aloha Beach as their vacation spot in "In Tents Debate". In "Picture Perfect", along with her sisters she gets annoyed with Lincoln over his perfect picture. In "Ties That Bind" she is worried like the rest of her siblings about being kicked out, and gets upset with Lincoln when he says out loud how "he's always wondered what it would be like to be an only child". In "Along Came a Sister", she, along with her siblings wants to prevent Frances from getting killed. In "Come Sale Away" she gives a blank stare to the camera when the others continue to try and compete with each other to find her blanket.
Although still learning to talk, she seems to understand her brother and sisters quite often, such as when Luan wanted her to be a ventriloquist dummy. She is very cheerful, and loves to be near her siblings. She is most frequently seen in the care of Lincoln, Luna, Leni, and Lori.
It is implied that she is feminine like Lori, Leni, and Lola, as she wished to go to the beach, while Lincoln's tomboyish sisters wanted to go to an amusement park instead.
Despite her cheerfulness, she isn't above fighting back if rubbed the wrong way. In "Brawl in the Family", she chastises Lincoln for continuing to butt in Lori and Leni's feud and later gets in a big fight with her sisters after Lincoln reveals things some of the sisters said about each other. In "Room with a Feud", after Lori accidentally steps on her phone, she retaliates by posting a humiliating photo of Lori online.
In "Any Given Sundae", she is proven to be very protective of her family's safety so she can make sure that they are not getting into trouble, fearing that her parents punished them by not giving them ice cream.
"Lily Loud may be the smallest member of the Loud House, but what she lacks in size, she makes up for with her stinky surprises. She's a professional diaper ditcher, and loves drooling on everything. Even though she's known as The Poop Machine, Lily is everyone's favorite little buddy!"
As the youngest of the Loud siblings, Lily is very small, and usually just wears her diaper. She has one prominent tooth, and a tuft of blonde hair on her head.
On occasions where she wears clothes, she wears a lavender t-shirt (lavender being the color she seems to wear the most) and blue pants. In "Linc or Swim", her swimwear is a lavender onesie with a picture of a strawberry on it, in the same episode, she wears a blue swim diaper with yellow ducks on it. Her nightwear consists of lavender footie pajamas. Her snow clothes is a lavender parka, with purple shoes, and gloves.
Early in development, Lily had a tall poofy tuft of hair. Later on, however, that tuft of hair was made shorter. The early design would later be the basis for Billy.
Like all babies, Lily wears a diaper to cover her lower area. She often defecates in it, causing one of her siblings or parents to change her into a fresh one. She often tends to take it off and run around naked, as her title as a professional diaper ditcher would indicate.
Lily has a small lavender blanket, with purple frills on the edges. So far, it has had two major roles in the series:
In "Changing the Baby", Lincoln tried to implement his interests into Lily, since none of the other sisters had the same interests as him. When Lincoln believes Lily has changed, he tosses the blanket away, claiming she doesn't need it anymore. Later, when the siblings were trying to win Lily over with their own interests, Clyde, thinking Lincoln is replacing him with Lily, tries to win back Lincoln, by dressing up as a baby himself. Lily notices that Clyde is clutching her blanket, so she crawls over to Clyde to get it back. Seeing Lily do this makes Lincoln realize that the blanket is her own interest, and decides it's best not to change Lily, due to her attachment to the blanket.
In "Come Sale Away", the siblings got into a contest to see who could sell the most stuff during their garage sale. However, when they manage to sell all their stuff, Lily begins to cry. Lincoln notices that she needs her blanket to calm down, but when he and the other sisters can't find it, they assume that they accidentally sold it during their garage sale. When Lincoln and the sisters try to find the blanket, they notice that Flip has it. However, when they all arrive back home, they realize that blankets they got were actually rags that Flip gave them just to con them out of their money. As the siblings began to complain, it is shown that the blanket was at the house all along, as Rita was just washing it.
In a world where Lincoln has 10 brothers instead of sisters, Lily is a baby boy named Leon.
Much like his female counterpart, he has light blonde hair and usually wears only a diaper. However, unlike Lily, his hair is shorter, and he has more teeth. He also doesn't have any eyelashes like his female counterpart. In the dimension where Lincoln is the middle child of eleven sons, Leon is shown to be rather mean to Lincoln, much like the rest of their brothers, but in the dimension with Linka, Leon is shown to be caring towards his sister. Much like how Lincoln tends to have a fatherly attitude towards his youngest sister, it can be assumed that Linka has a very motherly attitude towards her youngest brother.
Like all of his male siblings, Leon eventually ceases to exist, when it is revealed Lincoln's whole adventure was just a dream.
Lily's superhero form is the Deuce.
In "Pulp Friction", she fights off Wild Card Willy's goons with her dirty diapers.
Despite having one tooth, Lily does have a full set of teeth when she is grinning or scared.
While not as intelligent as her sister, Lisa, Lily seems rather intelligent despite being only fifteen months old, as she seems to have a pretty good understanding of what is going on around her.
Lily is left-handed.
Since she's a baby, Lily cannot properly speak yet.
Lily is usually shown without eyebrows, much like her male counterpart Leon Loud, though Leon has no eyelashes and one extra tooth.
However, in several episodes, such as most of her Season 4 appearances, she has visible eyebrows.
Based on her appearance during "Luan Loud's April Fool's Highlight Reel" in "April Fools Rules", she could've been born sometime during January, February or March as the video was of last April Fool's Day.
Lily's hair looks similar to the cowlick on Lincoln's hair.
Luan, Lincoln, and Lisa all have the ability to translate Lily's babbling.
At times, Lily displays a natural talent for photography, as shown in "Out of the Picture", when she provided Lola with a better school photo for the latter's yearbook, and in "Room with a Feud", when she took a grotesque picture of Lori before spitefully posting it online.
In "Out of the Picture", "Room with a Feud", and "Anti-Social", Lily was shown to have a pretty high knowledge of how to use technology, as she is seen using a tablet in the former episode, and a cell phone in the latter episodes.
In the episode "L is for Love", it shows that Lily has a romantic infatuation with her teddy bear, and that she has a talent for drawing, when she drew a picture of herself, and the teddy bear she had a crush on.
According to Lynn's Q&A, Lily beat her in a thumb war.
According to some information on the Loud House Instagram:
The one place in the world where she would want to go to is mama.
Her biggest pet peeve is "boo-boo", which either means something scary, or an injury.
In "Any Given Sundae", she can use her diaper to mop the floor. This episode also reveals that she can read numbers, although the game Welcome to the Loud House implies that she likely cannot read words, judging by the fact that when handed Lucy's book of poems, she doesn't even try to read it.
Coincidentally, Abril (Lily) is Cecilia Gómez (Rita)'s daughter in real life.
Lily's Italian dubber, Giada Bonanomi, also voices Lynn.
In the Latin American dub, the scene from "Come Sale Away", where Lincoln dismisses having accidentally sold Lily's blanket, has her saying "Lincoln malo, ¡quiero mi mantita!" ("Bad Lincoln, I want my blankie!") instead of merely babbling like in the English version.
Lily's Filipino dubber, Marick Dacanay, also voices Lola (just like her English voice actress, Grey Griffin), but not Lana.