“Bad Girls Club” star Gia Sapp-Hernandez fights like a friggin’ Rottweiler … so says her accuser who told cops she took a BITE out of him during a brawl in South Carolina this weekend.

TMZ broke the story … Gia was arrested for assault Saturday morning after a violent incident outside of a nightclub.

Now, we’ve learned … witnesses told police Gia had been fighting with multiple MEN that night … including people she had been partying with earlier that evening.

Law enforcement sources tell us … when cops arrived on scene … one of the men told cops Gia chomped down on his arm during the ruckus … and he had a nasty bite mark to prove it.

After talking with witnesses and viewing the bite mark … cops decided to arrest Gia for assault and battery in the 3rd degree.

She was eventually released on a $2,130 bond.

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