Leni L. Loud is a main character in The Loud House.
At 16, Leni is the second oldest child in the Loud family. Unlike Lori, she is very naive, and is quite ditsy, but she makes up for it in beauty and kindness. Her most annoying habit is saying "like", which is ironic, as she doesn't actually say it that often.
Despite being the second-oldest of the Loud children, she is the most unintelligent. However, she is easy-going and happy-go-lucky. Various examples of her simple-mindedness are expressed throughout the series. In "Linc or Swim", she does not know the rules of the game, "Marco Polo", much to Luan's annoyance. In "Project Loud House", she is shown to be unable to walk and chew bubble gum at the same time. In "Changing the Baby", she gets stuck in Lily's crib and thinks that it's a prison. When she's being interrogated by Lincoln and Lucy in "Sleuth or Consequences", she thinks they're interviewing her, and states that her favorite color is zebra.
Despite this, she's shown to be skilled at fashion designing, wood carving, lock-picking, and making smoothies, which demonstrates that while she may not be very bright, she is creative, and artistically inclined. She is also the kindest out of the bunch, and gets along well with her siblings.
She suffers from arachnophobia, as seen in "Left in the Dark", and "No Guts, No Glori". This phobia is most prominent in "Along Came a Sister", where Lincoln brings his class's pet spider, Frances home. When Leni first sees Frances, she panics and attempts to kill her with bug spray. Later on it is revealed that Frances is still alive, and an Exterminator comes to dispose of her. Leni overcomes her fear, and cuts off the exterminator in order to save Lincoln's reputation - once again - showing that she has a big heart.
Leni has also proved that she can be irresponsible, as shown in the episode "Cover Girls". She agreed to cover for Luna, Luan, Lynn, Lucy, Lola, and Lana, and later passed the task onto Lincoln. However, Leni is shown to be very compassionate, as she was the only one of her siblings to prioritize helping her family get better, as opposed to getting away when the Loud family caught the flu in "One Flu Over the Loud House".
While she does have moments of inconsideration, like her out-of-character smugness in "Sleuth or Consequences", her good nature overshadows these moments.
"Leni Loud loves designing outfits and accessories to go with them. Leni's easily distracted by shiny objects, and often walks into walls while talking, but what Leni lacks in smarts, she makes up for in heart. She's the sweetest Loud around!"
Leni has long, pale-blonde hair with side-swept bangs. She is almost as tall as Lori. Her main outfit is a frilled seafoam green dress. With this, she wears red hoop earrings, white sandals topped with light green bows, and a pair of white sunglasses on top of her head.
Her night attire consists of a seafoam green nightgown, that looks very similar to her regular outfit, but sleeveless. She also sleeps with a magenta sleeping mask, but later on it changes to a blue mask with an image of closed eyes over it.
Leni's original design depicted her with a light blue dress, snow boots, as opposed to sandals, and a hairstyle that resembled Lori's, but was slightly longer.
In "Hand-Me-Downer" she was seen as a younger girl, but her wardrobe wasn't entirely different. She still wore a seafoam green dress, and sandals with green bows on them. The only differences are that her dress didn't have frilled sleeves, and she didn't have her sunglasses.
Leni wears her sunglasses atop her head in every episode she appears in. She only removes them when she goes to bed, if she showers, or goes swimming.
Her sunglasses are white, with two black circular lenses, and a shine going across both of them.
When she was portraying a cat in the family play in "Suite and Sour", her sunglasses were triangles in shape instead of circles which looked like cat ears.
There is an animation goof that has occurred a few times, where her sunglasses are missing in one shot, and then reappear in the next shot.
Alternate Versions and Alter-egos
In the alternate dimension where Lincoln has brothers instead of sisters, Leni is a boy named Loni. Like Leni, Loni is ditsy and dumb. Unlike Leni, he is thoughtless, and could care less if Lincoln, or his other brothers were hurt.
In another alternate universe where everyone is the opposite gender and Lincoln is a girl, Loni is shown to be caring and honest with Lincoln, like Leni.
Loni eventually ceases to exist, when it is revealed Lincoln's whole adventure was just a dream.
The 11 of Hearts
In the minicomic Deuces Wild!, Leni takes on the identity of the superheroine "The 11 of Hearts". She plays the role of one of Ace Savvy's sidekicks. Her signature weapons are heart ties with which she uses to tie up her foes. In the comic, she is summoned by Savvy alongside the rest of his deck to help him and One-Eyed Jack to defeat the gas monster. After they defeat it, they prepare to fight against a garbage monster.
The 11 of Hearts appears again in "Pulp Friction" along with the rest of the Full House Gang. During her appearance there, she saved Ace Savvy and One Eyed Jack from falling into a shark pit by using her pink bow as a rope.