Pic of cut off Human Head for sale!!! WTF!

The human head that was found in a Hollywood park Tuesday was photographed by a passerby ... and guess what -- the photo is being shopped around.

We've seen the pic -- no, we're not buying it.  But it appears to be a male's head with the hair still intact.  There's a lot of blood at the base and it does not look like it was cleanly cut off. 

The skin is very red and there is some decomposition. 

The head is laying on a bed of leaves, with several leaves covering a portion of the face.

The dog walker who found the head didn't have a phone to call the cops, so she asked a guy walking by if she could use his phone.  After he obliged, he took a pic of the head.

Cops are investigating.