The sickness began in Jake's head. Pain slowly built up on the inside and Jake tried rubbing the spot to ease the pain. Upon making contact with his head, however, his hand was hit with a jolt of pain that surged down his arm.
Jake couldn't move his arm from the spot; it seemed to be paralyzed. The skin in between his fingers felt like they were tightening, pulling on his fingers. He simply groaned in pain as his fingers began to shorten. The phalanges weakened and broke down, the floppy muscles and skin being pulled into Jake's palm.
Although the pain in Jake's head was not close to being gone, he still managed to open his eyes and move his hand in front of his face. Jake began to hyperventilate at the sight of the large, fleshy nub in front of him. His mind couldn't process whether or not he was dreaming; it was too much pain to handle. He reached to his neck to pull off his sweat-stained shirt only to find out that it too had been reduced to a stub.
Jake's whole body was heating up. He collapsed on the ground from the pain. He scrunched up his eyes and screamed at the top of his lungs.
It was at that point that Jake's feet began to feel strange. Jake did his best to look at his sandals. When he finally saw his right sandal, he almost gagged at the sight of his feet widening and becoming cramped inside his sandal. He pushed his foot down against the ground to push his sandal off. As soon as his foot was freed, Jake noticed that a flesh-colored webbing was present in between his slowly-flattening toes.
Jake screamed as loud as he could, tears in his eyes, as his legs began to lose muscle. He kicked his legs wildly as their thickness diminished. As the changes progressed, Jake's legs shortened to a shorter length than his arms.
The headache Jake had burned like fire. His head felt like it was losing mass to Jake- and it was. His forehead became shorter and shorter and his chin shortened in the same way. His face appeared to form small bubbles of skin (which, in reality, held quickly-growing stems). Jake shook his head as his neck lengthened and lost mass in a way similar to what happened to his legs. His ears wiggled and flapped wildly as they shrunk down into nothing but tiny holes on the sides of his head.
Jake stopped screaming suddenly. He felt something protrude from the inside of his mouth. His lips felt as if they were shrinking down a bit into his head as his gums seemed to stretch forward. Jake clenched his teeth together as his head felt as if it was about to burst. Slowly, his mouth closed as his teeth dissolved into thin air. Jake inched open one eye to see that his gums had become a hard, yellowish color and it was stretching into a large, flat duck bill. His nose inched its way into his head, his nostrils moving down above his bill.
The hair on Jake's head came next. Each strand on his head stiffened and thickened slightly into tiny tubes. With an audible crinkling noise, the tube-hairs on Jake's head bloomed into tiny green feathers. Each bump on Jake's face split open, more green feathers shooting out of them.
Jake's splitting headache became a numb pain, giving him a chance to move around a bit. He was speechless as he looked at his stubby arms, which were bent in a similar fashion to wings. A flurry of bumps appeared going down his arms which erupted into sleek, long grey feathers. He attempted to roll his new plump body over onto his legs. After a few unsuccessful attempts, he finally managed to get onto his feet.
A human-sized duck now stood where Jake the human had stood just minutes before.