Ron White is a calm, cool and collected comedian when he's onstage, but if you vandalize his tour bus in the middle of the night ... he becomes a half naked maniac who'll chase you down with a golf club.
TMZ got this photo of White apparently coming after a guy who was doing the dirty deed. Underwear? Don't care ... and we're told he pulled a gap wedge out of his golf bag, Elin Nordegren style.
As we reported ... a man was arrested after he sideswiped Ron's bus with his truck.