Terrapin – any of several species of North American fresh-water or tidewater turtles characterized by a horny beak, a shield covered with epidermic plates, and partly webbed feet

“[Roosevelt] weighed eight and a half pounds and began life as a hearty baby, bright and hyperactive. His mother remarked that he looked like a terrapin, but he was soon declared a beautiful child, blond and blue-eyed.”

Lion in the White House, Aida D. Donald