Flavius Josephus, War of the Jews book 4, chapter 9.

"They also devoured what spoils they had taken, together with their blood, and indulged themselves in feminine wantonness, without any disturbance, till they were satiated therewith; while they decked their hair, and put on women's garments, and were besmeared over with ointments; and that they might appear very comely, they had paints under their eyes, and imitated not only the ornaments, but also the lusts of women, and were guilty of such intolerable uncleanness, that they invented unlawful pleasures of that sort. And thus did they roll themselves up and down the city, as in a brothel-house, and defiled it entirely with their impure actions; nay, while their faces looked like the faces of women, they killed with their right hands; and when their gait was effeminate, they presently attacked men, and became warriors, and drew their swords from under their finely dyed cloaks, and ran every body through whom they alighted upon. However, Simon waited for such as ran away from John, and was the more bloody of the two; and he who had escaped the tyrant within the wall was destroyed by the other that lay before the gates, so that all attempts of flying and deserting to the Romans were cut off, as to those that had a mind so to do." Flavius Josephus, War of the Jews Book 4 Chapter 10.

https://www.ccel.org/j/josephus/works/war-4.htm

The Account of The priests of the Galli as recorded by James Frazer in his book "The Golden Bough"

"While the flutes played, the drums beat, and the eunuch priests slashed themselves with knives, the religious excitement gradually spread like a wave among the crowd of onlookers, and many a one did that which he little thought to do when he came as a holiday spectator to the festival. For man after man, his veins throbbing with the music, his eyes fascinated by the sight of the streaming blood, flung his garments from him, leaped forth with a shout, and seizing one of the swords which stood ready for the purpose, castrated himself on the spot. Then he ran through the city, holding the bloody pieces in his hand, till he threw them into one of the houses which he passed in his mad career. The household thus honoured had to furnish him with a suit of female attire and female ornaments, which he wore for the rest of his life."

Link to page 820, Quote taken from page 823.

https://archive.org/details/the-golden-bough-in-12-volumes/James%20George%20Frazer%20-%20The%20Golden%20Bough%20%282009%2C%20The%20Floating%20Press%29%20-%20libgen.li/page/820/mode/1up?q=Galli

Additional information on the Priests of the Galli by ancient origins.

https://www.ancient-origins.net/history-ancient-traditions/galli-0017397

Galatains 5: 19-21

"19 Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, 20 Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, 21 Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God."

https://www.biblegateway.com/passage/?search=Galatians%205&version=KJV