Green’s Dictionary of Slang

of a person, squat, thickset; thus as a nickname for such a person; also used of a small object.

1856		M.J. Holmes ’Lena Rivers (1878) 253: Darned if you don’t look like aunt Nancy, only she’s lean and you are squatty.
1867		G.W. Harris Sut Lovingood’s Yarns 136: She wer fat enuf to kill [...] Well, a-stoopin to kiss that squatty lard-stan ove a gal is what dun hit tu me.
1910		Spokane Press (WA) 27 Mar. 5/2: One end of the squatty shack [...] serves his faithful old horse as a stable.
1928		R. Fisher Walls Of Jericho 207: ‘Don’ tell me – that jasper can fight.’ ‘Squatty’ll wear him down though.’.
1930		C.R. Shaw Jack-Roller 51: Tony was a squatty boy, rough features.
1936		R.F. Adams Cowboy Lingo 176: A short, fat person was apt to be called ‘Squatty’.
1949		R. Chandler Little Sister 47: He’s a little squatty number.
1957		C. Himes Imabelle 91: ‘He look just like her brother, don’t he?’ ‘Short, black and squatty,’ the tall man said.
1961		G.L. Coon Meanwhile, Back at the Front (1962) 171: I’ve been after Hedges for weeks to get in to see that squatty little bastard.
1984		J. Dailey Silver Wings (1985) 202: Mary Lynn pressed a squatty Coke bottle into Marty’s hands.