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. The guy was cited by cops, but he became enraged and started kicking the bus, denting it.
Ron wasn't having it, and summed it all up to us like this ... "Don't f*** with me when I've been drinking."