The prize for  Cynical_Gage of a Tails Weight Gain Animation.

In here, Tails is testing a new invention, the Adrenalverter, a device to convert energy of the body into energy for machines. Naturally, before he can use it in the field he needs to test it to make sure there are no side effects. He makes it to the Eating Test to see how it reacts while eating. He sets up a feeding machine by his couch and gets to work while a video camera records the whole thing.

As things start it seems like it is fine. Tails feels a bit tired as the device draws on his strength, though it is just as he figured from his previous tests. What he didn't count on was the added comfort of the couch and the constant feeding soon lulled him to sleep.

Almost an hour later, Tails awakens to find he is still in the middle of his feeding, but surprisingly the feeder has not only been at constant work, but it unexpectedly sped up. On top of that, a good deal of pudge has appeared on his body a surprising side effect the Adrenalverter appears to have had on his metabolism. The sudden shock causes Tail's heart to race causing the device to power up more causing it to short circuit and further increase the speed of the feeder. Tails is unable to even resist, his own energy being used to power the feeder. The camera gets destroyed as well due to the increased power of the Adrenalverter.

A while later Tails awakens again to find the feeder emptied and had already shut off and the Adrenalverter has broken and detached from him. As his mind comes into focus he discovers he's more than tripled in size and weight.

With the issue of quick weight gain from his device Tails cannot yet consider it yet for field use, but he's already onto his next project, Ordering Takeout and he sure seems to be enjoying himself.