Green’s Dictionary of Slang

jack in the box n.²

socks.

1935		A.J. Pollock Und. Speaks.
1960		J. Franklyn Dict. of Rhy. Sl.
1999		R. Walton ‘Cockney Jack’ 🌐 He got up and put on his throw me in the dirt, his wool fiddle and flute, his Jack-in-the-box and his daisy roots.