Yes it is real I wrote to Mr. Cosby and he signed the 8x10 and had his assistant send it to me. I have a huge collection of autographs and will auction off more depending on how well this one does.
Well I like Metallica however when it comes to autographs you can only get the ones from people willing and able to sign. I wrote the the ones I have via their agents or personal address and they sent the requested autograph. Some of the people I wrote to didnt reply back because they were busy or don't sign many autographs.