Frank J. Wilstach, comp. A Dictionary of Similes. 1916.

Sleek

Sleek and round as a German sausage.
—Peter. C. Asbjörnsen

Sleek as a dray horse.
—George Colman, the Younger

A skin as sleek as a maiden’s cheek.
—Eliza Cook

Sleek as Mr. Pecksniff.
—Charles Dickens

Sleek as a mouse.
—John Gay

Sleek as a cat.
—Maurice Hewlett

Sleek as silk.
—Thomas Hood

Sleek as a horn-book.
—Ben Jonson

Sleeker than Night-swollen mushrooms.
—John Keats