Damon Arnette -- who was cut by the Raiders after he recorded himself waving around firearms while threatening somebody -- has just been signed by the Dolphins.
The team announced the move Wednesday ... saying it's added Arnette to its practice squad just over one month after the Raiders released him.
The move is surprising -- because while Arnette, a former first-round pick, is talented, his off-field issues have certainly raised some concerns.
The 25-year-old defensive back has been hit with 2 lawsuits in the past year -- with one alleging he injured a woman during a car crash in 2020.