Fishy, no! Where oh where has my fish gone?

Was the puft overheating or chilled? I've seen the mobs die if they go too far out of their comfort zone.
 

It seemed to be fine, not exhibiting any signs of trouble.  It was just flying(swimming?) along, eating slime and dropping small balls.  First and only time I've seen one, so I'm not sure what is normal for it.

Hatch, those seem annoying, had a different game with two.  They seemed hostile, so I pit-trapped them, narrowed it down to a 3x tall and 1x wide area, then ran water into the pit til it drowned.

Poor Puft suck in air so it creates vacuum on its tile, and if the room pressure is low enough for the vacuum to persist for a little more time then its cool down the Puft to lethal temperature

1 hour ago, Lt.Warhound said:

Hatch, those seem annoying, had a different game with two.  They seemed hostile, so I pit-trapped them, narrowed it down to a 3x tall and 1x wide area, then ran water into the pit til it drowned.

And if you dropped him resources instead of drowning, he would make you coal and muckroot

I just had a puft disappear along with all the slime it created. Very sad...