"The Botticelli Horror" is a short story by Lloyd Biggle, Jr. It was published in Fantastic Science Fiction in 1960 and is set in an unspecified future. Humanity has colonized the universe, but people still live on Earth. As with real world countries, the smuggling of rare and exotic animals from planet to planet is a huge problem. Allen works as an inspector for a government agency known as Terran Customs, and he and his colleague Dr. Ralph Hilks have been sent to the Kansas town of Gwinn Center to investigate the grisly murder of two children and the maiming of a third: Sharon Brown, her sister Ruth and their friend Johnnie Larkins were attacked by something that killed the two sisters and left Johnnie, the child who survived, legless. Only one girl's head has been left behind, along with the kids' shoes; even the shoes of Johnnie, who lost his legs, were left. Local physician Dr. Anderson can't identify what could've attacked the three.
The local authorities, Commissioner Cornley and Sheriff Townsend, are blaming Elmer, a giant Venusian snail owned by a man named Bronsky who regularly performs in a local carnival; Elmer can shapeshift, and his most popular act is to form himself into a replica of the figure from Sandro Botticelli's painting The Birth of Venus, owing to his shell. Allen and Hilks are on hand to ensure Elmer was brought to Earth legally and whether Bronsky can be held responsible for the snail's crimes... assuming he did in fact kill the children.
Allen is skeptical. He knows a lot about alien wildlife, and although Elmer did escape from the carnival around the same time that Sharon, Ruth and Johnnie were attacked, nothing about the attack matches what he knows about giant Venusian snails, nor does it square with Bronsky's insistence that Elmer is gentle and friendly. His suspicions are confirmed when the surviving child, Johnnie, gives a description of what attacked him and his friends that doesn't even remotely describe Elmer, and Allen realizes that they're dealing with an illegally imported Venusian Night Cloak, a flying creature that envelopes its victims and eats them, with a tendency to only ever leave their shoes behind...
The story has seen reprint a few times, such as in Monsters, the eighth installment of Isaac Asimov's short story collection series, Isaac Asimov's Wonderful Worlds of Science Fiction, as well as another short story collection Asimov put together (he really seems to have liked it!), Fantastic Creatures.
This story provides examples of:
- Absentminded Professor: Dr. Hilks' Establishing Character Moment is him being so absorbed in reading a scientific journal during the plane ride that he momentarily forgets where he and Allen are going.
- Asteroids Monster: The soldiers shoot the Night Cloaks to pieces, thinking they've won and stopped the invasion... only for the individual pieces to arise as more Night Cloaks, doubling their numbers.
- Covers Always Lie: The Fantastic Science Fiction cover makes it seem as if Elmer is the threat, considering how sinister Elmer's Venus imitation is drawn, and the manner in which the man in the foreground (Allen?) is recoiling in horror from it.
- Death of a Child: The Night Cloaks' first victims are three children, two of whom die.
- Detect Evil / Evil-Detecting Dog: Because Venusian snails are the natural predators of Night Cloaks, Elmer can sense whenever one is near.
- The Dreaded: Night Cloaks are feared throughout the universe.
- "Eureka!" Moment: Two. First when Allen realizes what kind of aliens they're dealing with based on Sole Survivor Johnnie's description of the thing that attacked him and his friends, and later when Private Walker realizes that the reason Night Cloaks don't eat shoes or boots is because they're made of leather, and Night Cloaks don't like leather, allowing the Army to make leather uniforms for the soldiers.
- Friend to All Living Things: Johnnie. When Allen visits him in his hospital room, the boy is playing with several birds and squirrels who came in through the open window to play with him, suggesting he has a natural way with animals.
- Gentle Giant: Elmer. When the cops first think he killed the kids, a visibly upset Bronsky (his owner) insists Elmer is too sweet-natured and friendly to have done such an awful thing. He turns out to be right; not only are Night Cloaks the real killers, but when Allen meets Elmer himself at the end of the story, the big snail is quite friendly and even shapeshifts into a human form (Allen's) so he can shake the inspector's hand.
- Hollywood Acid: The Night Cloaks have a digestive acid that can eat through pretty much anything in a matter of seconds, although they tend to leave leather and other things cured by tannic acid alone.
- Hydra Problem: As a result of the Night Cloaks being Asteroids Monsters.
- Mauve Shirt: Private Walker. The way he's introduced wondering whether he'll die and only his boots will be found suggests that Biggle is setting him up as the next victim, but not only does he survive, but he even figures out a way to make inedible clothing for the soldiers to wear so they can more effectively fight the Night Cloaks.
- Men Are the Expendable Gender: Mostly played straight considering that there aren't any major female characters (most of the people who encounter the Night Cloaks are, after all, soldiers), but of the three children who get killed at the beginning, only the little boy, Johnnie, survives, while girls Sharon and Ruth die.
- Museum of the Strange and Unusual: Professor Dubois' alien lifeform museum at the carnival.
- Picky People Eater: Night Cloaks eat everything that they envelope except for the person's shoes or boots. These are always left behind.
- Redshirt Army: General Fontaine's troops are pretty much just in the story to die. That is, until Walker figures out a way to make inedible leather uniforms for them.
- The Scapegoat: Until the Night Cloaks are discovered as the true culprits, the authorities blame Elmer for the deaths of the children, due to his escape coinciding with their deaths. In reality, he only escaped because he sensed the Night Cloak that killed them nearby.
- Start to Corpse: The story begins with Allen and Hilks arriving and visiting the scene of the attack against the three kids. Besides their shoes, all that's left of them is one girl's head.
- 20 Minutes into the Future: It's set on a realistically futuristic Earth at some unspecified point in history after mankind has taken to the stars and colonized other planets. Life on Earth goes on, however, and the fashion, language and technology is still roughly contemporary to the 1960s, when the story was written. The Army doesn't use laser guns, for example, and Allen and Hilks arrive in Gwinn Center aboard an ordinary private plane.
- Voluntary Shapeshifting: Elmer's main ability. He can form the soft parts of his body into a nearly perfect imitation of anyone or anything, right down to the color; when imitating Anderson during his act, for example, he even forms the clothes the doctor is wearing and gets the color of his tie right.