Green’s Dictionary of Slang

cray adj.

[abbr. crazy adj. (2)]

(US black) a general intensifier, wonderful, extraordinary etc.

Jay-Z & Kanye West ‘Niggas in Paris’ [lyrics] That shit cray, ain’t it Jay?
[US]Eble UNC-CH Campus Sl. Spring 2014. 15 June [Internet] Cray Cracy Note that the white mainstream use favors reduplication (so cray cray) whereas the AAE use does not (tha shi cray ‘That shit is crazy’).
67 ‘Waps’ [lyrics] Dip, dip, dip, dip, from qway dipping's been cray.