Green’s Dictionary of Slang

a general oath, lit. ‘God’s hooks’ (cf. cotso! excl.).

1690		D’Urfey New Poems 135: Pray shew us dear Daddy how we were begot. / God zoukes, you young Jades, 'twas the first Oath I wot.
1705–07		N. Ward Hudibras Redivivus I:1 24: I trudg’d along as fast, Cotzooks, / As Porter with a Billet Doux.
1709		‘Poem on the Taking of St. Mary’s’ Collection of Eng. Poetry II (1716) 7: Cotzooks, my Dear, why what’s the meaning?
1731		Beau’s Misc. 51: Cotzooks, my Dear, why, what’s the Meaning?