The area of South London known as "Elephant and Castle" gets its name from the Infanta di Castille, or "The child of the castle" in English. Specifically, "Infanta" referred to the eldest daughter of a Spanish monarch without a claim to the throne, and in this case, it was Eleanor, wife of Edward I but originally from Castille. Much like Victora two hundred years later, the newly expanding area was named after the current queen.
The area of South London known as "Elephant and Castle" gets its name from a local cutlery company in the area from the 18th century. They made ivory-handled forks and spoons, and so their logo was an elephant with a howdah on its back. The howdah is a kind of oversized saddle with a roof on, and looks a little bit like a castle. If you squint. The logo of the The Worshipful Company of Cutlers also features an elephant and howdah/castle.