Pretty Butterflies

Some people view most insect types as Big Creepy Crawlies that are scary at best, or dangerous and scary at worst.

Butterflies, however, have always gained positive interest from humanity, given their beautiful colors, their graceful flying, and the fact they look like they would rather drink nectar from flowers than star in the next B horror film. They became symbols of the wind, reincarnation, transformation, the soul, and magic throughout the ages. As a result, butterflies have appeared numerous times in many media.

Examples:

Anime & Manga

The first episode of Kimba the White Lion has the titular character lost at sea, so he followed a swarm of migrating butterflies to get to land.
Golden Butterflies show up a lot in Umineko no Naku Koro Ni. Seeing them usually means you're very big trouble.
Though they don't get a lot of screen time, one must not forget the black Hell Butterflies that escort the Soul Reapers in Bleach
- Averted oh so hard with Szayel Aporro Granz though. His normal, human-like form is actually rather handsome but when he goes One Winged Angel butterflies will no longer be beautiful to you. They will be hideous, blood-like monstrosities with very pleasing voices and the ability to use you as their next cocoon.

Comics

Neil Gaiman's character Delirium is fond of creating or turning herself into butterflies.

Film

Mothra is a giant butterfly goddess and is also one of the more peaceful (And one of the few purely good) Kaiju out there.
- Then there's her more violent counterpart Battra. He's just trying to protect the environment, but thinks destroying all of humanity is the best way of doing so.

Literature

In The Patchwork Girl of Oz, a boy named Ojo had to get the left wing of a butterfly for use in a potion, but the Tin Woodman wouldn't let him harm the butterfly.
The Doctor Who books have a room in the TARDIS that is simply filled with butterflies.
Discworld has the Quantum Weather Butterfly which looks spectacular flying en masse, but the ensuing super-storm caused by the flapping of the wings less so.
- The novel Interesting Times also has a character named Pretty Butterfly; as per standard Pratchett subversions she is downright manipulative and violent. This may be the result of growing up with a name like 'Pretty Butterfly'.
Subverted in A Fire Upon the Deep by Vernor Vinge, where there is an alien race who resemble beautiful butterflies -- and they're a bunch of genocidal fascists.
Not strictly butterflies, but China Mieville's Perdido Street Station has a race of giant mind-eating (psychophagic?) moths. They're not strictly pretty either.
The contagious serial-killer curse from Red Iron Nights causes its host to belch clouds of green carnivorous butterflies.
Animorphs had The Departure, where Cassie got a butterfly morph.
- one of the TV series eps used butterfly morphs as well.
In Nathaniel Hawthorne's short story Dr. Heidegger's Experiment, four aged people are revitalized by water from the Fountain of Youth, as is a dying butterfly drenched in the liquid. The butterfly's sudden relapse signals that this happy reprieve - and, by implication, life itself- is only temporary. Butterfly = Brevity of Existence is the probable symbolism.

Live Action TV

Averted on Modern Family, as Manny is afraid of butterflies.
On NCIS Complete Monster Ari Haswari briefly mentions being afraid of them.

Newspaper Comics

In Prickly City, Carmen and Winslow are admiring a pretty butterfly when Kevin interrupts to demand they stop lallygagging.

Video Games

The Pokémon series includes several butterfly-like Mons, including Butterfree, Venomoth, and Beautifly.
- Although subverted with Beautifly: it's an aggressive predator that feeds by sucking out the prey's bodily fluids.
The first Persona game has Pandora, whose final form is a giant, bipedal butterfly.
- The series as a whole loves its butterfly motif; Philemon, a major character in the first three games (counting both halves of the second game), has Butterfly of Death and Rebirth as his his major gimmick, and is never seen without a butterfly mask. The save points in the fourth game even are butterflies (which according to Word of God are Philemon's current manifestation).
Odin Sphere has Phozon Butterflies which your character can absorb to power themselves up.
Yuyuko of the Touhou series employs butterfly Danmaku in your final showdown with her in Perfect Cherry Blossom.
Let's Go Jungle. After fending off swarms of Giant Spiders (including a gigantic one), as well as other carnivorous creepy crawlies, and a Man Eating Plant, your Final Boss is a giant butterfly. Who then proceeds to smack you around with swarms of butterflies, cut you with its wings and blow you off the helicopter you're on...
Earthbound features magic butterflies that will restore your HP and PP along with some soothing music.
Dark Souls features a boss called Moonlight Butterfly. It is a nice departure from all the brutally dangerous looking bosses you have been fighting! During the fight, the typically epic music of the boss fights is replaced with calm, soothing music. It is a dangerous creature if one is careless, and doesn't carry a shield with good magic defense, as it uses magic attacks such as lasers, magical spears, Homing Soul Arrows, and explosive bursts.
Dahlia Hawthorne in Phoenix Wright Ace Attorney Trials and Tribulations is accompanied by butterflies to emphasize her sweet, delicate demeanor. They spontaneously combust the moment she reveals her true colors.

Webcomics

Inverted with Mistress Butterfly from Collar 6, who sticks butterfly symbolism all over the place but is actually a Manipulative Bitch In Sheep's Clothing.
Roza conjured them.
In Sinfest, butterflies are usually symbols of transformation, but sometimes they are just pretty.
- As when Squigley sees them under the influence.
In Tales of the Questor, the Cool Sword Wildcard produced an array of them -- causing Quentyn's foes to laugh -- for the crucial seconds before the rooster crows, meaning they can no longer attack him.

Web Original

Swallowtail from the Global Guardians PBEM Universe is a powerful and effective Powered Armor-wearing superhero whose suit is yellow and black and has rather glorious-looking gold-foil butterfly wings (they act as stabilizers when she flies).
SCP Foundation-408, a sentient Hive Mind flock of butterflies whose wings can change colors as both an effective illusion and way of communicating.
An Easter Egg on one of the Potter Puppet Pals has Ron frolicking with butterflies while singing "Follow the butterflies, follow the butterflies...."
- Taken from a sarcastic comment Ron made in Harry Potter, after finding out that he and Harry would have to "follow the spiders", assumedly making him wish for a less scary and more harmless insect to follow.
In Megami 33's Sailor Moon Abridged, the ridiculousness of having the characters attacked by butterflies in one episode is underscored by the "sound effect" of people saying "flutter, flutter, flutter...." very peacefully.

Western Animation

SpongeBob SquarePants has Wormy, Sandy's pet caterpillar who transforms into a butterfly. But since there are no butterflies underwater, everyone thinks it's a hideous monster.
In a discussion of reincarnation, Bart Simpson said he wanted to come back as a butterfly, "because no one suspects the Butterfly of Doom!"
The Monarch.
Taken advantage of in Anastasia -- When Anya is on the ship to France, Rasputin's demonic minions masquerade as butterflies to draw her into a sleepwalking, Tastes Like Diabetes dream that will end when she leaps to her doom in the ocean.
" In my world, Everyone's a pony, and they all eat rainbows, and poop butterflies".
Jimmy Two Shoes: Heloise creates butterflies...that explode on contact.
Alice in Wonderland featured Bread-and-butterflies. And later on, we see the Caterpillar turn into a um, guess.
- "THE MUSHROOM, OF COURSE!!!"
Gypsy Moth from A Bugs Life.
- At the end of the film, Heimlich (an overweight caterpillar who speaks in a German accent) actually emerges out of his cocoon as an overweight butterfly with teeny-tiny wings. Because his wings are too small for him to get off the ground, Manny (Gypsy's husband, who is a praying mantis) and Francis (a disgruntled male ladybug who has being referred as a female) had to help him up as the circus bugs fly away.
Fluttershy out of My Little Pony Friendship Is Magic has these as her 'cutie mark'; she's also saved by a lot of them when she ends up falling as a filly. She's one of the kindest characters in the series as well.
Chuckie of Rugrats and Loopy in Ka Blam's "Life With Loopy" both tried to become beautiful by turning into butterflies.

Real Life

The Butterfly House in Aberystwyth, Wales.
Down here in California is where the Monarchs migrate on their way down to Mexico. Some places are literally covered with them.