Wedgwood referred to this squatty basalt creamer as their "St. Louis" shape.  A classical sprig group on each side provides the primary decoration: "Sacrifice to Aesculapius," god of  medicine and "Ulysses Staying the Chariot of Victory," hastening the defeat and capture of Troy.  Additional detail includes a wreath of laurel around the nose and additional leaf detail where the handle joins the body. 

An interior glaze seals the semi-porous basalt, indicating the useful intent of the piece.

Robin Reilly in Volume II of his work on Wedgwood reproduces pages from a catalog of black basalt, circa 1914 which include a teapot, cream and sugar in this shape identified as "St. Louis."  Reilly notes, however, that all shapes shown were in production before 1900 (pp.450,451).