Bicorn is a demonic unicorn with two horns. The number 1 supposedly represents the purity of man, and 2 represents the seductions brought with the arrival of women. Bicorn supposedly represents adultery. It is said that the unicorn was born from a bicorn and once had two horns itself.
"A monster with two sharp, spiraling horns on its forehead, considered the counterpart of the unicorn. Males are called bicorns, while females are called chichevaches ("thin cows"). If unicorns are considered holy, then bicorns are considered unholy, reviled as filthy beasts. The number 1 is said to signify the purity of man, while the number 2 represents the seduction brought by the arrival of women. This dualistic nature has proved especially influential in Japan. Unicorns are said to have originated from bicorns, and once had two horns themselves. They are also thought to have been invented later as symbols of good to oppose the "evil" bicorns. Bicorns are said to symbolize adultery, one of the Seven Deadly Sins."
—Shin Megami Tensei IMAGINE compendium
Bicorn can be contracted in the Nakano field and within the Nakano Stone Site. It is one of the mountable demons within the game and one of the few that has two different nimble variations.
"An evil creature with two curving horns. It represents impurity, unlike the Unicorn. Said to be derived from Re'em in the Bible. Another legend says that it feeds off of disloyal husbands."
—Persona 5 background
Bicorn is the first Persona of the Hermit Arcana and can be found as a Shadow in Kamoshida's Palace, with the title "Dirty Two-horned Beast." It is the first Persona to learn the Lunge, Tarunda, Garu, Ice Wall and Apt Pupil skills. When itemized through Electric Chair execution in the Velvet Room, Bicorn produces a Garu skill card.
Three Bicorns will surround the party during their second foray into Kamoshida's Palace and defeat the protagonist and Morgana prior to Ryuji's awakening. Eligor will summon two Bicorns during the boss battle with him as support afterward.
"A horse like beast with two helical horns on its head. While the Unicorn represents purity, the Bicorn is its opposite. Its origin is unclear, but some believe it is derived from Re'em, the dual-horned beast in the Old Testament."