I was viewing the Perseid Meteor Shower on the evening of 08/12/15, between the hours of 2200 (08/11/15) to 0130 (08/12/15). My location was Mt. Laguna, CA, 91948 (whose coordinates are: 32 deg 48 min 30 sec N by 116 deg 26 min 51 sec). My elevation was approximately 3000 ft.I was facing the Eastern sky and was able to see the Milky Way, Andromeda Galaxy, Pegasus, Pleiades, etc. As I was looking on the NW side of the Perseus Constellation I saw what appeared to me to be a comet. It was heading towards the constellation, approximately 7 deg away from it. What I viewed was about the size of a softball, oval shaped, green in color, and it had a tail.I do not believe it was a meteor or an alien craft. I am an avid amateur astronomer who has seen many comets over the years; Hyakatuke, Halleys, Hale-Bopp, to name a few. Therefore, I do believe I know a comet when I see one. Also, I have viewed lots of other celestial sights, such as the Beehive, the Double Cluster by Cassieopeia, Andromeda Galaxy, Great Orion Nebula, etc..((NUFORC Note: We spoke via telephone with the witness, and he sounded to us to be quite eloquent and sober-minded. We suspect that he is an excellent witness. PD))