Along with fellow Cragmoloid Noba, Ook was kidnapped in Cragmoloid native world Ankus, and both of them soon ended in the slave "zoo" of slaver Phylus Mon (who could have kidnapped them in the first place). They had to learn Basic language during their imprisonment, and they reached an acceptable level. As of around 20 BBY, after an unspecified time as slaves, both of them still suffered from homesickness.
The person in the next cell, Shistavanen assassin Bin Kohal, considered the size of Ook and Noba for a possible escape plan: The Cragmoloids were so big that they would take up a lot of space in any escape ship. A massive escape would have to include more than one ship.
Phylus Mon surgically inserted an explosive near the heart of each of his slaves. The explosive would be activated in the case of Phylus Mon's death, but it could also be deactivated with the impact of an ion weapon. All the slaves in Phylus Mon's zoo were also regularly battered.