The Oculus Rex is the largest and most powerful of all the oculi species, and the Imperial Oculus Rex (sometimes called “Oculus Imperius”) is simply an even larger, older, and more powerful version.

Besides the large central or “main” eye, an oculus rex has seven lesser eyes on short stalks arranged in a crown-like fashion. These lesser eyes are limited in their viewing angle, but despite that fact they reduce the chance that one can be surprised to just 1 chance in 1d8 if the opponent is visible.

However valuable this resistance to surprise may be, it is the least of the powers granted by the many eyes of an oculus rex. The main eye projects a beam that dispels magic (as the spell) in a conical area 60 feet wide at the base and 120 feet long. This power functions constantly, virtually guaranteeing that all spells will eventually be ended, all potions and scrolls destroyed, and all permanent magic items suppressed in just a few rounds. The spell effect is applied as if the oculus rex were a spellcaster of the same level as its number of hit dice.

The remaining eye effects are generally distributed as listed below, where the first eye listed is the eye just to the monster’s right of center in front and proceeding around to the eye just to the left of center in front. About 20% of individuals have their eyes arranged in the opposite order, and one in a hundred (i.e. a roll of 00 on the dice) have them arranged randomly.

The eye powers are as follows. Note that all spell effects are applied as if cast by a Magic-user of the same level as the monster’s number of hit dice. Each eye can use its listed power once per round.

Figuring out which eyes an oculus rex can use in a given encounter can be tricky. Please review the example diagram to help you see how to work this out.

The gray area in the diagram shows what part of the battlefield around the monster can be targeted by eye number 2 (the slow eye, normally). This does not mean that all creatures in the area are targets at the same time, but rather that only those creatures within the area can be targets of that eye.

Of course, the oculus rex can turn around whenever it wants to, but in the interest of fairness it should only be allowed to turn once per round, before performing its attacks.

An oculus rex can suffer the loss of any of its lesser eyes without also suffering a loss of hit points. Severing an eyestalk requires 8 hit points of damage, or 12 hit points for the larger oculus imperius. Any successful hit to the monster’s main eye which inflicts more than one-third of the monster’s total (original) hit points in damage renders that eye useless. The monster regenerates slowly, such that any individual that survives an encounter will regrow any lost or damaged eyes (even the main one) and all will become functional when its hit points reach the normal figure once again.