Srange faeces in my garden

Hi. Can anyone help identify the faeces left in my back garden a couple of days ago? It was about 3 inches long, approx one third "standard " grey/whitish poo, two thirds black spaghetti like strands. Some separate black "spaghetti" strands also found nearby. Photos are attached. Wildlife in my garden normally consists of birds, some rabbits, an occasional snake and we back onto woods so foxes and deer are quite common down our lane, although I have never see any in our garden. I appreciate that this site is mainly for birds but don't think this is from a feathered friend, however maybe someone has come across something like this before. Thanks