Is gravy really made from animal blood mixed with fat?

Of course blood and fat are involved in meat gravy. Gravy is mixing the juices that come from meat (or vegetables), collecting it and usually thickening it with flour or corn starch and adding spices of choice. With meat, gravy is typically the blood that oozes from the meat as it is cooking. The fat that is included is what you will allow. I personally trim as much fat as possible before I cook to ensure that my gravy has lower levels of saturated fats than the gravy from untrimmed meat.

Improving on previous answer:

"'No, that is disgusting! Besides, i am becoming a chef, and the first thing i learned how to make was gravy. Its simply, really!"