Carroll’s earliest sketches (above) of the Mock Turtle show a creature with faceted armature that looks very little like a turtle. His depiction of the Gryphon is likely based on a finished drawing by his brother, Wilfred (below).
Lewis Carroll (1832–1898)Preliminary sketches of the Mock Turtle and GryphonDrawing (pen-and-ink on paper), 1862-1864Photography: Christ Church Library© Governing Body of Christ Church, Oxford
Wilfred Dodgson (1838–1914)GryphonDrawing (pen-and-ink on paper), ca. 1862-1864Photography: Christ Church Library© Governing Body of Christ Church, Oxford