At the beginning of Part II, Frye's creature is running through the woods until eventually wearing down. After the creature "Hulks-In" back to normal, Frye is miraculously wearing shoes. This is impossible as the creature was barefoot.
Obvious stunt double each time Del Frye is being hit by Brad Wheeler.
When bad Hulk throws a rock toward the deer it hits the water just missing it, not only dos it bounce on the water it stays afloat. Rocks don't float, they sink.
When Frye's Creature is attacking Brad and Earl at the bar Earl is hiding behind a column. When the creature throws a couple of trash cans at him he is no longer behind the column but under the front window.
When Earl is hiding behind the column you can see a poster behind him. It is flipped and his position keeps changing from scene to scene.
When Frye's Creature knocks down the tree, the prop line pulling the tree down is visible.