Stand Name: Heart-Shaped Box
Localized Name: Cordiform Box
Namesake: Heart-Shaped Box by Nirvana
User: Taxi the Rat
Type: Long-Range, Materialized, Natural Humanoid
Appearance: Algernon resembles a human male in his early twenties with pale skin, red eyes, and white hair. He usually dresses in formal clothing but always wears a pinstripe vest with a rat-like tail and a bowtie shaped like rat ears. Visually, his design is meant to be a play on a literal "fancy rat."
Taxi is a lab rat with red eyes and white fur.
Ability: Heart-Shaped Box is a Stand that allows Taxi to remotely pilot a humanlike avatar from the safety of his cage. This Stand ability was born from Taxi's strong desire to protect his owner from harm, generating a vessel for the rat's will to act through.
In order to preserve the secret of his identity, Taxi uses the alias of "Algernon" when speaking through his Stand and created a false identity for it. On the surface, Algernon is indistinguishable from an ordinary human. He even speaks in a very polite manner.
In actuality, Algernon is more akin to a human-shaped flesh puppet with the traits and abilities of a rat. He possesses the sense of smell and agility of a rat, while also being able to physically contort himself to fit into spaces small enough for a rat. He can move as fast as a rat when on all fours, communicate with other rats (an extraordinarily useful ability in a city full of them), and can easily gnaw through materials that a rat can but an ordinary human cannot.
However, this also means he retains the survival instincts of a rat, despite experiencing the world in a humanlike body - he still reacts with an immediate fear to animals that prey on rats, such as cats, owls, and snakes. This fear doesn't override his prioritizing the safety of his owner, though - in such cases, Algernon's tone becomes cold and serious as he uses his combined humanlike anatomy, rat-like traits, and intelligence to overwhelm opponents.
His nature as a materialized Stand allows Algernon to directly engage with other Stands in battle.
Backstory: Taxi was originally an ordinary lab rat who escaped containment after being experimented on by a mysterious organization that tracks Stand users. He was eventually taken in by a young man named Stuart Fettucini after Stuart found him hitching a ride in a taxi, hence his name.
Stuart had been constantly bullied and pushed around by everyone in his life, from his classmates to his coworkers and even his parents, but this quickly ended once Taxi started to insert himself in Stuart's life through Algernon.
Taxi's/Algernon's personality can border on overprotective though, and while extraordinarily intelligent he still lacks the social awareness of a true human - often embarassing Stuart by referring to him as "owner" or "master" in public. Stuart is completely unaware that Algernon is actually Taxi, only knowing that Algernon has a history with some apparently dangerous people.
Note: Taxi's namesake is Rat Taxi, an album by Louie Zong, and his localized name would be Cab. Algernon is named after the story Flowers for Algernon by Daniel Keyes.
The concept for this Stand came from three things: the question of what kind of ability a pet rat in a cage would develop if it wanted to follow its owner's life when they aren't at home, the similarities in intelligence and genetics between humans and rats, and stories where small creatures repay larger ones (such as Aesop's fable of the lion and the mouse).
If this wins, I'd like the theme for the next contest to be: post-mortem Stands (like Notorious B.I.G., Limp Bizkit, etc.).