Origin
Preta, also known as "hungry ghost" or "gaki", originate from Buddhism. They are people who have reincarnated into humanoid creatures due to unjust deeds committed in their past lives. They are prone to wandering off into the human realm after being sent to one of the six realms: The Hungry Ghost Realm, a realm where Preta reside.
As punishment for their karma, they are inflicted with the inability to eat. Due to the thin size of their neck; if they succeed, the food will ignite in their mouth. They may also be attacked by animals, or driven off by bigger, stronger demons such as Oni. Among the most notorious punishments is being cursed with an insatiable hunger for something inedible such as human waste. Preta aren't invisible to the human eye. However, in a Preta-centric Theravada Buddhist story, The Petavatthu, it is mentioned that people such as monks can communicate with them.
The depictions of Preta vary but in a Japanese scroll called the Gaki-zoshi, they are portrayed as grotesque with thin limbs and a large swollen stomach. They are illustrated slightly taller than humans. The Preta have a variety of skin colors: black, dark blue, yellow, and beige. The scroll also depicts them naked while the others wear fundoshi.
Design
Preta's design varies in each game.
His debut in Shin Megami Tensei has a monstrous appearance; having three fingers with sharp claws, purple skin, and a large swollen stomach.
Last Bible, portrays him as a short ghoulish demon with beige skin and large lips.
In Shin Megami Tensei: Devil Summoner, he has purple skin, and a swollen stomach. This design also features an elongated chin, two golden bracelets, red ofuda, and a messy bowl cut.
His design in Devil Summoner: Soul Hackers is the same but a color swap with brown skin, gray bracelets, and yellow ofuda. This design is more faithful to the Preta depicted in the Gaki-Zoshi scroll.
Preta typically has visible but censored genitalia. However, for the 3D Shin Megami Tensei appearances it is left uncensored while in other games such as in Devil Summoner: Raidou Kuzunoha vs. King Abaddon it has been removed entirely.
Shin Megami Tensei V
Main Story
On a street in Tamachi, the Nahobino discovers a fairy-like demon named Amanozako who is cornered by three Preta. As the Nahobino approaches, they notice his presence while one of them demands to know who he is. The protagonist does not respond just as Amanozako hides behind a wall while spectating. The Preta believe that Nahobino will take their "food" away and attack as they threaten to slap him on their menu.
A Preta Predicament
Inside a cave to the northeast of Tamachi, the Nahobino discovers a group of starving Preta, who complain about being hungry. Speaking with the Preta Leader, he asks for his buddies to be found, demanding they get back the cave with food.
In Mita, a wandering Preta is seen scavenging underneath the trees. When asked he says that refuses to go back to the cave. He is afraid of what will happen if he returns without any food. Reporting back to the cave in Tamachi, the leader then asks the Nahobino to search for another Preta, that he believes is in Shiba.
Arriving at a cave on the east side of Shiba, a lone Preta is seen worshiping Apsaras alongside many Cait Sith and Kodama. When spoken to the worshiper replies that he has food but refuses to go back as he has “found his own path”. He gives the Nahobino Sake and Dango Medley asking him to deliver it.
Returning to the cave in Tamachi the Preta are excited about the food. They gather the group around the campfire for a feast. However, the feast does not last long as the devoured food leaves them unsatisfied. They then ask the Nahobino if he has anything more to give them. When he refuses, the group attacks.
After defeating them, they apologize for their behavior and give him the Haunt Talisman.