Dave Mustaine claims to have written `` Leper Messiah '' on the album Master of Puppets , and his name is not featured in the song 's credits .
`` It was the last album to feature songwriting contributions from former lead guitarist Dave Mustaine something which he disputes as he claims to have written `` '' Leper Messiah '' '' on Master of Puppets , a song which does not feature a Mustaine credit . ''