Tyrannabyss
Huge Aberration (Aquatic)
Hit Dice: 5d8+15 (35 hp) 
Initiative: +6 (+2 Dex, +4 Improved Initiative) 
Speed: 10 ft., swim 60 ft. 
Armor Class: 14 (-2 size, +2 Dex, +4 natural) 
Attacks: 4 tentacles +9 melee, bite +7 melee, stinger +1 ranged 
Damage: Tentacle 1d4+6, bite 1d6+3, stinger 1d4+3 and paralysis 
Face/Reach: 10 ft. by 20 ft./10 ft. 
Special Attacks: Stinger, paralysis 
Special Qualities: Regeneration 1, camouflage, 1/2 damage from blunt weapons, contraction 
Saves: Fort +3, Ref +2, Will +2 
Abilities: Str 23, Dex 14, Con 17, Int 8, Wis 11, Cha 6 
Feats: Improved Initiative, Multiattack 
Skills: Hide +8 (+12 due to camouflage), Move Silently +8, Swim +12 
Climate/Terrain: Temperate to warm aquatic and coastal 
Organization: Solitary (1) or school (2-4) 
Challenge Rating: 5 
Treasure: None 
Alignment: Always neutral 
Advancement: 6-10 HD (Huge)
 
The tyrannabyss is found in salt water and coastal areas. Of average intelligence, it knows that land creatures are a good source of food and often explores buildings near the shore in hopes of an easy meal. Likewise, it may climb aboard a ship for a quick snack. 

A tyrannabyss resembles a 20-foot long slug with a toothy maw surrounded by four 10-foot long tentacles. Beneath its mouth is a small opening from which it fires its stinger. Its slimy hide is rubbery and grey, and it leaves trails wherever it passes. Preferring to attack with surprise, it uses its eyestalks to look around corners, peek through doors, and peer above the surface of the water. 

Combat: A tyrannabyss attacks by flailing with its tentacles. It attempts to bite anything close enough for melee, and it can fire its stinger every 4 rounds. 

SA -- stinger: The stinger can be fired a maximum of 15 feet and has a range increment of 5 feet. It causes 1d4+3 damage and delivers a paralytic poison. The tyrannabyss takes 3 rounds to retract the stinger, allowing an opposed Str check each round to break free. Anyone breaking free suffers an additional 1 damage from the barb tearing free. When completely reeled in, a victim is subject to automatic bite attacks. The stinger tentacle has AC 14 and can take 8 points of slashing damage before being severed. 
SA -- paralysis (ex): Anyone struck by the stinger must make a successful Fortitude save (DC 16) or be paralyzed for 2d6 rounds. 
SQ -- regeneration 1 (ex): The tyrannabyss regenerates 1 hp each round it spends in salt water. 
SQ -- camouflage (ex): This grants the tyrannabyss a +4 circumstance bonus to Hide checks. 
SQ -- contraction (ex): The tyrannabyss has no bones or solid organs and is able to squeeze itself through openings much smaller than its apparent size. As a general rule, if a Medium-size or larger creature is able to fit through an opening, so is the tyrannabyss. 

Source: "The Keep at Koralgesh" from Dungeon #2 
Converted by Kajal, the Southern Oracle