Eye of the Deep (CR 8)

Large Aberration (Aquatic)
Alignment: Usually lawful evil
Initiative: +4; Senses: all-around vision, darkvision 60 ft., Listen +19, and Spot +23
Languages: Common, Beholder, and Aquan

AC: 18 (-1 size, +9 natural), touch 9, flat-footed 18
Hit Dice: 12d8+48 (102 hp)
Fort +10, Ref +4, Will +10
Speed: 5 ft., fly 20 ft. (good), swim 30 ft.
Space: 10 ft./5 ft.
Base Attack +9; Grapple +18
Attack: Eye rays +8 ranged touch and claw +14 melee
Full Attack: Eye rays +8 ranged touch and 2 claws +14 melee and bite +11 melee
Damage: Claw 1d8+5, Bite 1d8+2
Special Attacks/Actions: Baleful flash, constrict 2d6+5, eye rays, improved grab, persistent image
Abilities: Str 20, Dex 10, Con 18, Int 12, Wis 14, Cha 15
Special Qualities: -
Feats: Ability Focus (baleful flash); Alertness; Great Fortitude; Improved Initiative; Multiattack; Weapon Focus (claw)
Skills: Listen +19, Search +20, Spot +23, and Survival +2 (+4 following tracks)
Advancement: 13-20 HD (Large); 21-30 HD (Huge); 31-36 HD (Gargantuan)
Climate/Terrain: Cold aquatic
Organization: Solitary, pair, or cluster (3-6)
Treasure/Possessions: Double standard

Source: Lords of Madness

Baleful Flash (Su): As a free action, an eye of the deep can generate a flash of terrible white light from its central eye once per round. This flash affects all creatures in a 60-foot cone. The baleful flash blinds creatures for 2d6 rounds and stuns them for half the duration of the blindness. A DC 22 Fortitude save negates the stun and reduces the blindness to dazzled. Sightless creatures are immune to this attack. The save DC is Constitution-based.

Constrict (Ex): An eye of the deep deals 2d6+5 points of damage with a successful grapple check.

Eye Rays (Su): Each of an eye of the deep's two small eyes can produce a magical ray once per round as a free action. A beholderkin of any kind can tilt and pan its body each round to change which rays it can bring to bear in any given arc. Each eye's effect follows the rules for a ray. Each ray has a range of 150 feet and a save DC of 18 (caster level 12th). The save DCs are Charisma-based. The two eye rays include:

Hold Monster: The target must succeed on a Will save or be affected as though by the spell.

Cone of Cold: This works like the spell, but affects only the creature touched by the ray (Reflex save for half).

Improved Grab (Ex): To use this ability, an eye of the deep must hit with its claw attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Persistent Image (Sp): As a standard action, an eye of the deep can create a persistent image (as the spell at caster level 12th). The eye of the deep cannot use its eye rays in the same round that it casts persistent image.

All-Around Vision (Ex): Beholderkin are exceptionally alert and circumspect. Their many eyes give them a +4 on Search and Spot checks, and they can't be flanked.

An eye of the deep uses its baleful flash ability and eye rays to hinder foes at range so it can swim up close and tear them apart with its massive claws.

Aquatic Subtype

Creatures with the aquatic subtype always have swim speeds and thus can move in water without making Swim checks. An aquatic creature can breathe underwater. It cannot also breathe air unless it has the amphibious special quality.