Dolly, a ewe, the first mammal to have been successfully cloned from an adult cell. Dolly, a ewe, the first mammal to have been successfully cloned from an adult cell. Dolly, a ewe, the first mammal to have been successfully cloned from an adult cell. Dolly, a ewe, the first mammal to have been successfully cloned from an adult cell. Dolly, a ewe, the first mammal to have been successfully cloned from an adult cell.