The biggest cat I have ever known belonged to my aunt who lived with my father's mother. A big black cat, Shadow would eat and eat every chance she got. Tuna fish as a treat, canned and dry cat food on the regular. The odd mouse here and there.
I knew Shadow when I was a child, back before my allergy began. Shadow was too skittish to ever get close to me but would often curl up in my grandmother's lap while she did a crossword or brush against her legs whilst cooking.
Like any cat, Shadow knew the sound of the electric can opener well and would materialize at once as it began to whir. Shadow passed away long before my grandmother was replaced by a smaller cat which was not overfed. Maybe Shadow was so big because I was so small.