Tower raven. There's 7 of them with clipped wings. The 7th is a spare. They're kept because of the legend that the kingdom and the Tower will fall if the 6 resident ravens ever leave. The protection of the Tower ravens was started by Charles II. The Raven is perched on remnants of the Inmost Ward wall.

White Tower (1100): One of the inner buildings inside the Tower of London.

Tower of London guard standing in front of Queen's House (1540).