Zookeepers are non-player characters who work at the Ardougne Zoo. They keep watch over the animals and clean up after them. Players can talk to a zoo keeper named Larry to start the Cold War quest and can also talk to a zoo keeper named Charlie to start the Eagle's Peak quest.
Zookeeper is the solution to the medium anagram clue: EEK ZERO OP. The answer to his challenge scroll is 40.