The crew's Jolly Roger is depicted a crescent moon and a skull.
The only named member of the crew is Gally himself. He has two crew members who are often seen accompanying him, but they are not named.
The Gally Pirates are strong enough to pose some threat to a small town. Their captain, Gally, seems to be stronger than the rest of the crew and is a famed pirate in the East Blue as one of the "Big Three" pirates. The crew was no match for Luffy, including their captain, who was easily defeated.
Romance Dawn, Version 1
The Gally Pirates were first seen approaching a small town after being captured and tied up by Monkey D. Luffy. They were later seen escaping from their bonds before being defeated by Luffy, who also destroyed their ship.
Whole Cake Island Arc