Green’s Dictionary of Slang

croak n.

[croak v.2 (1)]

1. supposed final speeches from the gallows and murderers’ confessions, usu. as peddled by street-sellers and possibly written by a hack journalist.

[UK]Hotten Dict. of Modern Sl. etc.
[UK]Sl. Dict. 361: Would you lend me the price of 2 Gross of Tops, Dies or Croaks, which is 7 shillings.
[UK]A. Barrère Argot and Sl. 272: The criminal... would perhaps utter for the edification of the crowd his ‘tops, or croaks,’ that is, his last dying speech .
[UK]Burnley Exp. 8 Aug. 4/8: The last dying speeches hawked about the streets were ‘tops’ or ‘croaks’.

2. a dying speech.

[US]‘O. Henry’ ‘Strictly Business’ in Strictly Business (1915) 13: Jack Valentine was the only person with the ranchman when he made his (alleged) croak.

3. (also croaking) death.

[US]‘Hugh McHugh’ Out for the Coin 28: I don’t see why he should come back after the croak and haunt me.
[US]‘Ellery Queen’ Roman Hat Mystery 72: Gawd, you’re not tryin’ to tie this croakin’ around my neck, are you?
[US]R.L. Bellem ‘Poison Payoff’ Hollywood Detective Dec. [Internet] ‘How’s the private-detective business?’ [...] ‘Lousy, thanks [...] It’s getting so I don’t know where my next croaking’s coming from.’.

4. (US) a boring complainer, a whinger.

[US]H.I. Dodge Yellow Dog 58: Spot the main croaks [...] Slip ’em the yellow card [HDAS].

5. (US drugs) a mix of crack cocaine and cocaine.

Hartford Courant (CT) 1 Sept. A10/1: A new generation of narcotics known as crank, croak and moon rock is invading American streets [...] corak [is] a mixture of crack and regular cocaine.

In phrases

do a croak (v.) (also pull the croak chain)

to die.

[UK] ‘’Arry in ’Arrygate’ in Punch 24 Sept. 133/1: If it hand’t a bin for my nunky, our pal might have just done a croak.
[US]St Louis Post-Dispatch (MO) 3 Dec. 17/7: Street Slang [...] To ‘croak’ is to die’, while to ‘do a croak’ and ‘to do a gun croak’ mean to be shot.
[US]M. Groening on Tracy Ullman Show [Fox-TV] Passed away...kicked the bucket, pulled the croak chain, had a meeting with Mr. Grim [HDAS].
do a gun croak (v.)

(US) to shoot oneself dead.

[US]St Louis Post-Dispatch (MO) 3 Dec. 17/7: Street Slang [...] To ‘croak’ is to die’, while to ‘do a croak’ and ‘to do a gun croak’ mean to be shot.
L. Mead Word-coinage 167: ‘To croak’ is to die; whereas ‘to do a croak’ and ’to do a gun croak’ mean to be shot.
on the croak

(US) on the verge of death, dying.

[US]A.H. Lewis Sandburrs 155: D’ last will an’ test’ment of a galoot he says is on d’ croak.