To determine the strangest item in The Joy of Cooking would just take too long, I think (though Page 515 would be high on the list, what with the line "If possible, trap 'possum and feed it on milk and cereals for 10 days before killing", and other recipes for porcupine or raccoon). But the "Birthday Bread Horse" is especially weird, if in an understated way:
"As our children have always demanded a piece of their birthday cake for breakfast, we concocted a bread horse to be supplemented later in the day by the candlighted cake of richer content... You will need a well-rounded loaf of bread.... Use the loaf for the body. Mount it on four of the candy sticks. Break off about a third or less of the fifth candy stick. Use it for the neck. Stick it into one end of the loaf at an angle. Put the oval rolls on the other end for the head. Use the braided rolls for the mane and tail, the raisins for eyes, the almonds for ears, and the piece of cherry for the lips. Bed the horse on leaves or grass. Add a ribbon bridle to keep this mad steed under some sort of control."