When the hippo is stalking K.D., Toronto and Randy, it's eyes are normal. When it's attacking them, the hippo has the white zoombie eyes. In the shot where the hippo swims away from them, the eyes are normal again.
When trapped by the crocodile, Hock throws away his gun, because the bullets can not harm the animal. In the next shot, the gun is back in his hand, without him having picked it up.
Blood stain from zombie porcupine quill on Brookes shoulder keeps changing in size from scene to scene. In one scene it will be about 1/2" and in the next about 3" then back to being 1/2" again. There is also no hole in the shirt from where the quill punctured it.
Jezel refers to crocodiles as amphibians. Crocodiles are in fact reptiles.
You can't tell that a woman is pregnant by looking at her blood in a microscope.