Shipwrecked

A boy ran through the deep vegetation, frantically fleeing from whoever - whatever - was chasing him; hunting him. It wasn't giving up, determinedly tracking him down like a hired assassin. It had superhuman speed and stamina levels of a professional athlete, never stopping in need of a breath of air, or a leg cramp.
It was unstoppable.

As a result of washing ashore a desert island, a boy finds himself in a challenging situation. Especially after something rapidly begins to follow his every move...