You are being watched

As I walk around Oxford and the  the Colleges, I often get the feeling that I'm being watched.  When I look up, I indeed see faces "watching" me.  All over Oxford's buildings are gargoyles (technically 'grotesques' as these don't spout water) - some in the shape of faces, some animals, some entire people. Many of them are quite funny looking.  I hear there is one that is even picking his nose but I haven't been told where.  The challenge is to find it among the thousands of gargoyles that watch over this city.