dandiprat A dwarf, midget, or pygmy. This archaic word was originally the name of a three halfpence coin issued in 16th-century England. It took on its present meaning when Richard Stanyhurst referred to Cupid as a dandiprat in his 1582 translation of the Aeneid.
go-by-ground A very tiny person, a homunculus, a Lilliputian. This obsolete expression is obviously derived from the little distance between the earth’s surface and a small person’s head.
I had need have two eyes, to discern so petit a go-by-ground as you. (Copley’s Wits, Fits, and Fancies, 1614)
hop-o’-my-thumb A diminutive person, a midget or pygmy; a mean, small, contemptible person, fit only to be ordered about and looked down upon. In early usage the term was primarily one of contempt; but, perhaps through confusion with Tom Thumb, it has become increasingly descriptive and less offensive, indicative of small stature rather than lowly status.
knee-high to a grasshopper Very short or small, especially because of a young age. This popular American expression and its many variants are jocular extensions of the simpler term knee-high, in use about 70 years before the earliest extended variant.
You pretend to be my daddies; some of you who are not knee-high to a grasshopper! (The Democratic Review, 1851)