Slither (2006)

From the depths of the endless space, a flaming meteorite crashes into the dark woods of the sleepy town of Wheelsy, South Carolina. As the scorched rock reveals its silent content--a baneful parasitic organism--a subtle alien invasion commences, and the war's unlucky first victim is the town's local businessman, Grant. Little by little, as an internal change transforms Grant into an utterly hideous monstrosity, his wife, Starla, starts to feel that something's been eating at him the last few days. Now, before the unstoppable extraterrestrial attack, no one is safe, and to make matters worse, Grant's transformation is far from over yet. Who can stop the slithering army from outer space?