Based on similarities to his other works, this tankard was likely designed by Charles Osborne, who worked for Tiffany & Co. from 1874 until 1887. A water pitcher sold in these rooms, 24 January 2020, lot 412, has a near identical base rim of shells and seaweed to that found on the present lot, as well as dripping seaweed and high relief marine motifs. A further example of Osborne's distinctive dripping seaweed and high chasing can be found on one of his trophies designed for the Goelet Bennett yacht races in the collection of the Indianapolis Museum of Art (Accession Number 2016.362).
Charles Osborne left a position as chief designer at Whiting Manufacturing Company to take a design position at Tiffany in 1878, where he worked until 1887. During his tenure at Tiffany, Osborne was known for his exuberant marine motifs and swirling forms, as described above, as well as his mastery of Japanesque design.