Toad in a hole; meat baked or boiled in pye-crust. He or she sits like a toad on a chopping-block; a saying of any who sits ill on horseback. As much need of it as a toad of a side-pocket; said of a person who desires any thing for which he has no real occasion. As full of money as a toad is of feathers.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Toad Eater * ToastNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes