He had his own fan club and was the subject of T-shirts and bumper stickers (most reading "Free Ken Allen").

In his book about animal resistance, author Jason Hribal writes that Ken Allen "would unscrew every nut that he could find and remove the bolts" in his zoo nursery.

Ken never acted violently or aggressively towards zoo patrons or animals except for another orangutan called Otis, whom he despised.

[5] The zookeepers decided to go "undercover," posing as tourists to learn Ken Allen's escape route, but the ape was not fooled and continued to evolve his tactics.

[7] In 1987, zoo officials hired experienced rock climbers to find every finger-, toe- and foothold within the enclosure, spending $40,000 to eliminate the identified holds.