The joke :
When I die, I want to be cremated.
It’s my last chance to have a smokin’ hot body.
This joke is a dark pun based on wordplay and irony.
Cremated means your body is burned after death.
“Smokin’ hot” is slang for someone who’s extremely attractive.
“Smokin’” literally involves smoke and fire.
So the humor comes from flipping expectations:
Obviously, being cremated means you’re dead — not attractive.
But the joke is that being burned is their “last chance” to be literally smoking and hot.
In short:
It’s funny because it mixes death, fire, and a phrase normally used for physical attractiveness, creating a clever and unexpected contrast.