Here ya go. I advanced a storoper from the Creature Catalog and updated it to 3.5 based on the 3.5 roper. I also chaged the immunity to ranged attacks to damage reduction. I didn't add the fiendish template because it gained so little. Instead, I advanced it another 6 HD. If you have your heart set on fiendish, we can downgrade it 6 HD and add the template.
Storoper (Advanced)
Huge Magical Beast
Hit Dice: 27d10+135 (283 hp)
Initiative: +4
Speed: 10 ft (2 squares)
Armor Class: 25 (–2 size, +17 natural), touch 8, flat-footed 25
Base Attack/Grapple: +27/+43
Attack: Strand +34 ranged touch (drag) or bite +29 melee (3d6+12/19-20)
Full Attack: 6 strands +34 ranged touch (drag) and bite +29 melee (3d6+12/19-20)
Space/Reach: 15 ft./15 ft. (50 ft. with strand)
Special Attacks: Drag, strands, venom, weakness
Special Qualities: Damage reduction 15/bludgeoning, darkvision 60 ft., immunity to electricity,low-light vision, resistance to cold 10, spell resistance 30, tremorsense 200 ft, vulnerability to fire
Saves: Fort +22, Ref +17, Will +14
Abilities: Str 27, Dex 11, Con 21, Int 12, Wis 16, Cha 12
Skills: Climb +28, Hide +22*, Listen +25, Spot +25
Feats: Ability Focus (venom), Alertness, Great Fortitude, Improved Critical (bite), Improved Initiative, Iron Will, Lightning Reflexes, Power Attack, Weapon Focus (bite, strand)
Environment: Underground
Organization: Solitary
Challenge Rating: 15
Treasure: No coins; 50% goods (stone only); no items
Alignment: Usually chaotic evil
Advancement: 22-30 HD (Huge)
The storoper (from "stone roper", also called "tar roper") is about 15 feet high and 6 feet in diameter, and appears to be a small statue of a roper. It is a cigar-shaped creature with 6 tentacles and a gaping maw, and weighs about 5,000 pounds. The storoper has a silicon-based, rocklike body.
If a storoper is killed and cut open, its treasure will be found inside the gizzard.
Storopers speak Terran and Undercommon.
Combat
If anything approaches within 50 feet of the storoper, it will attack by suddenly shooting out its tentacle strands; it prefers to attack two victims at once, each with three strands. The first two victims successfully attacked will be injected with the storoper’s venom. If the venom fails, the storoper will continue to hold the creature and the weakness will take effect next round.
Drag (Ex): If a storoper hits with a strand attack, the strand latches onto the opponent’s body. This deals no damage. If the storoper uses its venom attack and the target fails its save, it will release that creature so it can fight for the storoper. If the venom fails, or the storoper has already used its venom attacks for the day, it drags the stuck opponent 10 feet closer each subsequent round (provoking no attack of opportunity) unless that creature breaks free, which requires a DC 35 Escape Artist check or a DC 31 Strength check. The check DCs are Strength-based, and the Escape Artist DC includes a +4 racial bonus. A storoper can draw in a creature within 10 feet of itself and bite with a +4 attack bonus in the same round.
A strand has 10 hit points and can be attacked by making a successful sunder attempt. However, attacking a storoper's strand does not provoke an attack of opportunity. If the strand is currently attached to a target, the roper takes a –4 penalty on its opposed attack roll to resist the sunder attempt. Severing a strand deals no damage to a storoper.
Strands (Ex): Most encounters with a storoper begin when it fires strong, sticky strands. The creature can have up to six strands at once, and they can strike up to 50 feet away (no range increment). If a strand is severed, the storoper can extrude a new one on its next turn as a free action.
Venom (Ex): Twice per day, the storoper can secrete venom from each of its strands. A creature hit by a strand must succeed on a DC 30 Fortitude save or be paralyzed. A paralyzed creature will appear to have turned to stone (though in fact, it has not).
One round after being paralyzed, the victim recovers and must succeed on a DC 30 Will save or act in defense of the storoper (as if under the effects of a
charm person spell) for 2d4 minutes. A charmed creature will fight to the best of its ability to defend the storoper. The save DCs are Constitution-based.
If the storoper is killed, the victim affected by the venom will act as if under the effects of a
confusion spell for 1d6+2 rounds.
Weakness (Ex): After the storoper uses its venom, its strands function similar to a roper's strands. A storoper's strands can sap an opponent’s strength. Anyone grabbed by a strand must succeed on a DC 28 Fortitude save or take 2d6 points of Strength damage. The save DC is Constitution-based.
Skills: *Storopers have a +8 racial bonus on Hide checks in stony or icy areas.