Gamigin (ガミジン?) or Samigina (サミジーナ?) is a demon in the series.
In demonology Gamigin (also Gamygin, Gamigm or Samigina) is a Great Marquis of Hell who rules over thirty legions of demons. He teaches all liberal sciences and gives an account of the souls of those who died in sin and who drowned in the sea, speaking with a rough voice. He also answers what is asked about, and stays with the conjurer until he or she is satisfied. Gamigin is depicted as a little horse or a donkey, which changes form into a man under the conjurer's request. He is the fourth spirit of the Goetia.
"Origin: Israel. One of the 72 demons of the Goetia. He is a Great Marquis of Hell who rules over thirty legions of demons. He appears as a small horse or donkey. If he takes human form, he will speak on the liberal sciences in a rough voice. He can answer every question and will stay until all work assigned to him is completed. He especially excels in spiritualism."
—Shin Megami Tensei A-Mode DDS Dictionary
Devil Children White Book
An officer of Heaven's army that oversees the captured castle of King Frost in Ice Makai. After his lieutenant Principality is defeated he confronts Masaki Kuzuha personally. Although defeated, he warns that the Expanse will not be able to stand against Heaven's overwhelming power. He can later be fought as a regular encounter in Center Makai.