Which devil fruit is this, and what happend to it? During the punk hazard arc we can see one of the apples in the sleigh transform into a devil fruit just before smiley turns every thing in to a deadly gaseous goo. 
What happened to this devil fruit afterwards, and which devil fruit is it to begin with. Is it ever shown?
I can only answer this question partially because of the information we currently have on One Piece.

The name of the Devil Fruit is: Sara Sara no Mi, Model: Axolotl.
If you wanna look up the name, it can be found in chapter 673, page 12.

As for what happened to the Devil Fruit, I have no clue since neither the manga nor the anime have shown/hinted at it being transported afterwards. So it might as well still be on Punk Hazard.