Monster Rancher 4: Scientists explain that it loves the dark because it was originally developed to be a prison guard. It actually feels uneasy in bright, sunny places. Monster Rancher DS 2: Jail-Keeper is drawn to darkness. Scholars explain it was created this way so it could work as a prison guard. It may not be cheerful, but it has a very calm demeanor. My Monster Rancher: This combination of Golem and Zan might just have the power to destroy all monsters. A more powerful physique and glowing red eyes make this monster more impressive than even the normal Golem.