Legendary Ozzy Osbourne guitarist Zakk Wylde has obtained a long-term restraining order against an obsessed fan -- who allegedly left a creepy sacrificial offering outside Zakk's home. Zakk was in court Friday in L.A. -- where he testified his 20-year-old neighbor John Radich knocked on his door…

Heavy metal legend Zakk Wylde -- one of the greatest thrasher guitarists EVER -- claims he's "terrified" of an obsessed fan who recently left a "sacrifice" at his home ... this according to court docs obtained by TMZ. Wylde -- founder of the heavy metal band Black Label Society -- filed a request…