The Animal Liberation Front appeared in the Season Nine episode, "Free Willzyx". They are a group of eco-terrorists who use violence in order to obtain what they feel is best for the animals they are "saving".
While initially appearing to be a peaceful protest group who were applauding the boys' actions, it was later shown that they were willing to use violence in order to save the animal, even engaging in a shoot out with the police, killing two policemen as well as one of the Denver Sea Park Employees.
While varying in age and appearance, all members are seen wearing baseball caps, shirts, jackets, and buttons inscribed with the groups' acronym "A.L.F".
|Minor Characters from Season Nine|
| Animal Liberation Front | Doctor Lindsay | Dr. Biber | Jakartha | Karate Instructor | Nut Gobbler | Q-Money | Shauna | Sylvester Stallone | Tom Nelson | Wing Han Tsang|