The zombie roadkill animals were an army used by Darko Crevasse in his plan to destroy Halloween.
Before their apparent "death" the roadkill zombies were just typical nocturnal animals. After they were run over and came back the zombies had various tire marks, bruises, missing fur and other injuries on their bodies. Their eyes were also clouded over with potassium since their blood cells had stopped circulating.
Darko Crevasse had planned to use an army of nocturnal animals consisting of toads, racoons, Skunks, Cats, And Rats for his plan to ruin Halloween. Unfortunately, a truck ran them over and killed them. However, moments after Darko mourns his loss, the roadkill animals get struck by lightning, bringing them back as a zombie roadkill army. Darko becomes overjoyed that his army is alive and scarier than ever and goes through with his plan. Darko starts his plan by having the roadkill zombies destroy pumpkins all over town which attracts the attention of grossologists Ty and Abby. Darko then had the zombies attack the school where the grossologist managed to capture a few. Lab Rat discovered that the zombies are terrified of maggots. Ty and Abby attempted to use maggots to get rid of the zombies when they were attacking a bowling alley, but the maggots they had loaded into their blasters were too old and turned into flies too soon. Darko once again had the zombies attack the school, but the grossologists finally thwarted his plan by using younger maggots which in turn devoured the zombies leaving nothing but bone.
- The zombies were much more aggressive subsequent to being run over.
- Since their photosensitive eyes were clouded over with potassium, the zombies were no longer vulnerable to light.
- The zombies had an apparent phobia of maggots, as a zombie rat was shown to freak out when Lab Rat brought a maggot close to it.