Mr. Hopkins; a ludicrous address to a lame or limping man, being a pun on the word hop.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Hop-o-my-thumb * Hopping GilesNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes