Runehound (CR 3)

Medium Aberration
Alignment: Always neutral evil
Initiative: +2 (Dex); Senses: psychic scent, uncanny blindsight, and Spot +5
Languages: understands Undercommon, cannot not speak it

AC: 16 (+2 Dex, +4 natural), touch 12, flat-footed 14
Hit Dice: 5d8+15 (37 hp); DR: 5/silver
Fort +4, Ref +5, Will +5
Speed: 50 ft.
Space: 5 ft./10 ft.
Base Attack +3; Grapple +8
Attack: Bite +8 melee or vile spew +5 ranged touch
Full Attack: Bite +8 melee or vile spew +5 ranged touch
Damage: Bite 2d6+7, vile spew - see text
Special Attacks/Actions: Vile spew
Abilities: Str 20, Dex 14, Con 17, Int 5, Wis 12, Cha 8
Special Qualities: extended reach, fast healing 3
Feats: Combat Reflexes; Lightning Reflexes; Track
Skills: Hide +5, Move Silently +3, Spot +5, Survival +1 (+21 when tracking), and Swim +5
Advancement: 6-9 HD (Medium); 10-14 HD (large)
Climate/Terrain: Temperate marshes
Organization: Solitary, pair, or pack (3-8)
Treasure/Possessions: None

Source: Monster Manual III

Vile Spew (Ex): A runehound can produce two noxious substances that it can spit with tremendous force. It can emit a stream of acid that deals 1d6 points of damage for every Hit Die the runehound possesses (5d6 for a typical specimen), with a DC 15 Reflex save halving this damage. Alternatively, it can spit a glob of glutinous goo that acts as a single-target web spell; a DC 15 Reflex save negates the effect. Both attacks have a range of 100 feet, require a successful ranged touch attack, and can be used once every 1d4 rounds. The save DC is Constitution-based.

Reach (Ex): The serpentine neck of a runehound is long and powerful, giving the creature a reach of 10 feet with its bite attack; this reach also allows it to threaten a 10-foot-radius area. Because of the flexibility of its neck, the runehound can attack adjacent foes with no penalty.

Psychic Scent (Su): A runehound tracks by following psychic trails and aura traces. It gains a +20 bonus on all Survival checks made to track. It does not receive this bonus against mindless creatures or creatures shielded against mental effects.

Uncanny Blindsight (Su): Runehounds are blind but perceive their surroundings with their psychic senses. This ability provides a runehound with blindsight out to 500 feet. In addition, a runehound cannot be flanked.

Runehounds are cunning and tenacious creatures. If an enemy does not possess ranged weapons, a runehound will attempt to use its speed to flank its opponents, staying out of reach while using its acidic spew to injure its foes. Against a foe with ranged weapons, the hound will use its sticky spew against the strongest ranged combatant and then close as quickly as possible. It makes maximum use of its reflexes and extended reach, striking out against any creature that moves through its threatened space.