Bill Cosby's star on the Hollywood Walk of Fame isn't going away despite his sexual assault conviction ... but that doesn't mean it's safe from vandals.
Somebody took what looks like a permanent marker to add their own branding to the disgraced comedian's star -- adding the words "SERIAL RAPIST." and "#METOO."
As we reported ... the Hollywood Chamber of Commerce says Cosby's star will stay put on the famous Walk of Fame ... even after he was sentenced to 3 to 10 years in prison and deemed a "sexually violent predator."
His star had already been defaced once earlier this week with the words "SERIAL RAPIST" ... but it was quickly removed. It's unclear how long the latest graffiti will remain.