Note: This pilot was eventually adapted into the first part of the dub's Digimon: The Movie ("Highton View Terrace, Japan - 8 years ago"), and is probably the portion that went through the least amount of cuts.
This was actually the original pilot for the series that would eventually become Digimon Adventure, and was aired on television one day before Adventure's first airing in Japan. It's also very much canon, as it's a heavy plot point in Adventure.
Images of a large dinosaur and giant bird appear, and a boy narrates about how several years ago, he first met a Digital Monster...
In the middle of one night, a young girl named Hikarinote stares at the computer as a large egg made of data appears on the screen. Her older brother Taichinote , on the way back from the bathroom, catches Hikari looking at the screen, and the egg emerges from the computer...
In the morning, the siblings' mother goes out, and Taichi sees Hikari clutching the egg in her sleep. As Taichi makes breakfast for himself and his sister, who chooses mostly to communicate by blowing the whistle around her neck, he wonders what to do with the egg, since nobody will believe them that it came out of the computer.
While eating, Hikari drops the egg, and the egg begins to roll on its own until it goes into their own bedroom, stands straight up, and hatches into a small black creature (Botamon) that immediately latches itself onto Taichi's face and then runs around the room and under the bed. Hikari and the black creature communicate by blowing her whistle and blowing bubbles respectively, and afterwards Taichi speculates on what kind of creature it could be as it wolfs down everything Hikari gives it. The phone rings and Taichi goes out to answer it, but nobody turns out to be on the other line...and when he returns to the bedroom, the black creature has now turned into a somewhat larger pink creature, which also poops.
Hikari takes the food from the family cat, Miko, to give to the pink creature, and in happy gratitude the creature latches onto Hikari and then Taichi's faces before scarfing down the cat food. Miko, angry at having its food taken, comes into the room and attacks the pink creature, and when Taichi intervenes, he and the creature get scratched on their faces for their trouble.
At night, the mysterious creature talks to Hikari and reveals that its name is Koromon. (This Koromon is not to be confused with the one who would become Taichi's partner in Digimon Adventure.) Hikari introduces herself and her brother to Koromon, while Taichi is surprised to see that the thing can talk. Koromon latches onto Hikari and Taichi's faces again as a "sign of friendship" shortly before getting down and pooping again.
During late night, electronics in the area go crazy, and Hikari wakes up Taichi with her whistle to show him that Koromon is looking very odd. Koromon retreats under the blanket and emerges as a large yellow lizard-dragon (Agumon), who is so large he breaks the bed. The situation is not helped by their (very drunk) father coming home and insisting on coming in to give them goodnight kisses. The Agumon opens the window and Hikari mounts his back against Taichi's warnings, and the two of them jump off the balcony and onto the street.
Taichi runs out of the house and after Koromon and Hikari, while Koromon breaks open a vending machine, from which Hikari retrieves drinks from. Koromon continues to wander around the street with Hikari on his back, while Hikari asks him why he's not talking to her anymore. Koromon breathes fire at and destroys a nearby phone booth, while Taichi finds the broken vending machine and searches for Hikari.
Hikari begs and successfully gets Koromon to not destroy a truck, but he then spits three fireballs into the sky. Taichi sees the fireballs heading for his apartment complex and follows them, while Hikari asks Koromon to take her home. The electronic devices in the area go berserk, while a number of other children who reside in the building look up at the sky. Another egg, this time gigantic, appears in the sky and hatches to reveal a giant bird, which Koromon attacks and chases. Koromon and the giant bird confront each other and Taichi catches sight of them; he tries to get Hikari to come back home with him, while Hikari is busy pleading Koromon not to fight. The bird releases a ball of thunder at Koromon, causing an explosion, and Koromon shields the two siblings.
The electronics and lights begin to go crazy again and Koromon emerges from the explosion as a giant orange dinosaur (Greymon). Having been shielded by Koromon, Taichi realizes that this is the "sign of friendship", and Koromon and the giant bird resume their fight while Hikari cries. After a fashion, Koromon takes too much damage and collapses. Hikari cries and tries to reach for Koromon, while the giant bird approaches. Taichi also begins to cry, but gets an idea after seeing Hikari feebly trying to blow her whistle and, taking the whistle from her, blows with all of his strength.
Koromon gets up, and Taichi urges him to fight. Koromon and the giant bird resume their fight and are enveloped in white light, only to disappear right after.
Once the light clears, Hikari calls for Koromon, yelling where he is. Taichi narrates that it was an encounter that passed by too fast with a monster that normally shouldn't have been in their world, and that's why he's here...
- Behemoth Battle: Koromon eventually transforms into a giant dinosaur-like creature (Greymon) and faces off against an equally gigantic bird monster (Parrotmon) in the climax of the short.
- Destructive Savior: Koromon fights Parrotmon to protect Taichi and Hikari, but he causes quite a bit of damage to his urban surroundings. But it would've undoubtedly been worse if Parrotmon won.
- Extremely Short Timespan: Takes place in one whole day, leading to Taichi's remark that the encounter with Koromon went by too fast.
- Eye Awaken: Koromon appears to be utterly defeated by the giant bird, but after Taichi blows the whistle with all his might, Koromon's eye dramatically opens after a pause and he's back in the fight.
- Lull Destruction: Koromon doesn't speak again after evolving into Agumon and beyond. Parrotmon doesn't speak either. They both get lines in the American movie, removing a lot of the sense of mystery surrounding them.
- Public Domain Soundtrack: Maurice Ravel's "Bolero" makes up nearly the entirety of the soundtrack (in the Japanese version).
- Theme Tune Cameo: In the dubbed version in Digimon: The Movie, when Kari and the Digimon play with each other with the whistle and bubble-blowing, they do so in the tune of the English dub Digimon theme song.
- Took a Level in Badass: Koromon gets beaten up by the pet cat Miko, with Taichi lampshading how pathetic that is. Koromon becomes far more impressive after evolving into Agumon and again into Greymon, gaining the power to take down a rampaging, lightning-shooting, giant bird.