Fire Tank Pirates

The Firetank Pirates are an infamous and notable rookie pirate crew discovered on the Sabaody Archipelago around the time the Straw Hat Pirates arrived there two years ago.

Crewmates
They appear to be based on a mafia family, and many of them are dressed in suits, with coats strapped to their shoulders, and/or wearing fedora hats. Hence they (or at least the captain), like Crocodile, have a look that is very much like the Italian mafia.

Crew Strength
All of them appear to be consistently armed with rifles, save for their captain, who has an army of men inside of him, who work his body like a fortress, thus giving him military advantages. It is shown that many ride horses into battle and some fire cannons from their captain's body.

You guys have already lost... in sheer military force.

It can be presumed that they are quite strong for them to have made it all the way to the Sabaody Archipelago and for their captain to have such a high bounty. They, like the Bonney Pirates, were completely unharmed by Kizaru's raid, though they did not encounter the admiral himself or the Pacifista. Their current fate is unknown since they were pulled toward a mysterious, gigantic black sphere in the New World. They also seem quite battle-experienced, knowing exactly what to do when facing off against marines.

Ship
Their ship seems to have a fortress theme, with several cannons at the bow. It has been coated with the Yarukiman resin, allowing it to submerge underwater by reducing its buoyancy, and withstanding the water pressure of 10,000 meters.