There's an artist who made an animation where some girl starts to grow a muzzle and a tail before inflating into immobile fat girl.
http://www.furaffinity.net/view/18509914/
After searching his gallery for a bit he did more TFs along with his inflation art even though they're rare.
Woman inflates before exploding into a fiery phoenix before looping over.
http://www.furaffinity.net/view/16804853/
Old poof TF he made long ago about a girl suddenly being a dog girl.
http://www.furaffinity.net/view/10166086/
Cat TF Inflation sequence.
TF 1
http://www.furaffinity.net/view/5334696/
TF 2
http://www.furaffinity.net/view/5338862/
Inflation 3
http://www.furaffinity.net/view/5343090/
Inflation 4
http://www.furaffinity.net/view/5352988/