Mice - In Ancient Rome, cute little dormice were a special treat enjoyed by the wealthy. They would be fattened up and cooked with honey and poppy seeds.
Black iguana eggs - The Mayans used to farm black iguanas for their unusual eggs. They had a rough leathery exterior, but the egg itself was all yolk and was considered quite a delicacy.
Torpedo fuel - Sailors during WWII used to drink an improvised cocktail called torpedo juice. It was a mix of lemon, pineapple juice, and the 180-proof (90%) alcohol used as fuel in torpedoes!
Savory jellied salads - Sometime around the end of the 19th century, people lost their damn minds. Anything that was edible was turned into a jelly.
Blood broth - Historical sources suggest that the Spartans used to consume an especially disgusting dish called Spartan black broth. It was made of pig's blood, salt, and vinegar.
Ambergis - In Europe in the 17th century, it was a luxury food item that the wealthy used to eat in cakes and pies.
Turtle soup - Turtle soup became a delicacy in Europe in the 18th century. The meat was compared to that of veal or lobster, and it was often served at banquets.
Ham in aspic - Ham in aspic was a dreadful dish popular in the 19th and 20th centuries. Aspic is a kind of savory jelly made from boiling meat bones.
Peacocks - Peacocks might seem decorative, but wealthy Europeans would pretty much eat anything back in the day. They also ate larks, starlings, and cuckoos.
Coca-Cola milk - Over in the UK, it was customary to mix Coca-Cola with milk. Imagine the color...