Possibly a shortening of carcass + it. Apparently not related to cark (“to worry”).
cark it (third-person singular simple present carks it, present participle carking it, simple past and past participle carked it)
- (Britain, Ireland, Australia, New Zealand, slang) To die.
- The guy was running, then he had a heart attack and carked it.
1989, Kathy Lette, Girl′s Night Out, →ISBN, page 86:
- He′d always bragged about carking it before he hit twenty. When he turned twenty, he escalated the date of his demise to twenty-five.
- 1998, Barry Westburg, Glenda & Me & Meathead Go For Broke, Rage of Angels: Expatriate Tales, page 74,
- If I hit the little shit too hard his parents could even sue me. There′s a fine line between self-defence and pure and simple mayhem. The little bastard might even cark it.
2010, Betty Webb, The Koala of Death, page 10:
- “Hi Bill. Zorah told you about Kate?”
- “That she carked it? Yeh.” Translation: That she died. Yeah.
- He flapped his hand in a go-away gesture and started toward the koalas, but not before I saw a haunted look in his eyes. Did he still care for Kate?