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Spider, Giant Trapdoor


Giant Trapdoor Spider CR 4

XP 1,200
N Large vermin
Init +2; Senses darkvision 60 ft., tremorsense 60 ft.; Perception +4

DEFENSE

AC 15, touch 11, flat-footed 13 (+2 Dex, +4 natural, –1 size)
hp 37 (5d8+15)
Fort +7, Ref +3, Will +1
Immune mind-affecting effects

TACTICS

Before Combat A giant trapdoor spider lies in wait in its hole for potential prey to wander by for hours or days at a time.

During Combat The spider lunges out at anything of size Small or Medium that disturbs its web trigger lines. It seeks to grab its prey as quickly as possible and pull it back into its hole to consume in safety. If it is not able to pull a creature into its hole within one round (either during the surprise round or the first full round of combat) it withdraws into its hole for safety. If it is not holding a meal it uses its strength to hold the trapdoor closed, increasing the DC to lift it from 25 to 29.

OFFENSE

Speed 30 ft., climb 30 ft.
Melee stabbing bite +6 (1d10+6 plus attach), consuming bite +1 (1d4+3 plus poison)
Space 10 ft.; Reach 5 ft.
Special Attacks surprise strike

STATISTICS

Str 19, Dex 15, Con 16, Int —, Wis 10, Cha 2
Base Atk +3; CMB +8 (+16 to maintain grapple); CMD 20 (32 vs. trip)
Skills Acrobatics +10, Climb +12, Perception +8, Stealth +4; Racial Modifiers +8 Acrobatics, +8 Climb, +8 Perception, +8 Stealth

SPECIAL ABILITIES

Attach (Ex)

When a giant trapdoor spider hits with its stabbing bite attack, its scimitar-length mandibles penetrate the target, holding it fast. An attached giant trapdoor spider is effectively grappling its prey. The giant trapdoor spider loses its Dexterity bonus to AC and has an AC of 13, but holds on with great tenacity. A giant trapdoor spider has a +8 racial bonus to maintain its grapple on a foe once it is attached. An attached giant trapdoor spider can be struck with a weapon or grappled itself—if its prey manages to pin the giant trapdoor spider then they may remove it.

Consuming Bite (Ex)

A giant trapdoor spider consumes its food with a secondary, smaller set of mandibles. These teeth are less pronounced than their larger, stabbing mandibles but possess a weak toxin in addition to the lesser damage they deal. A giant trapdoor spider generally does not attempt to use its consuming bite attack until it is safely within its burrow, away from other potential enemies or creatures which might attempt to steal its meal. This is a secondary attack.

Weak Poison (Ex)

When a giant trapdoor spider hits a creature with its consuming bite attack it injects a weak toxin which slowly paralyzes the victim.

Consuming Bite—injury; save Fort DC 15; frequency 1/round for 6 rounds; effect 1d3 Str; cure 2 saves. The saving throw DC is Constitution-based.

Stabbing Bite (Ex)

A giant trapdoor spider has a large set of curved, scimitar-length mandibles it uses for digging its tunnel and as its primary attack form. When attacking, it attempts to stab prey with these mandibles, holding them fast while it drags them into its hole to devour with its consuming bite.

A giant trapdoor spider may make one stabbing bite attack during the surprise round against a size Small or Medium target within 10 ft. of its hole. If this attack is successful it immediately backs into its tunnel to consume its prey. Re-entering the hole automatically causes carefully placed webs to trigger the trapdoor to close behind it, separating itself and its prey from any other creatures, allowing it to consume its prey safely.

Sudden Strike (Ex)

A giant trapdoor spider lays carefully hidden trigger webs in a 10 ft. radius around its hole. If a size Small or Medium creature comes enters this area it may make a free DC 24 Perception check to notice the trigger threads. If successful, the creature notices several fine threads on the ground. A successful DC 19 Knowledge (nature) check will reveal their true nature and purpose, as well as what lurks nearby. If the Perception check fails and the creature steps into the area it will momentarily find itself stuck to one or more trigger webs. These lines break quickly and easily but not before alerting the spider that it is now mealtime. The ground suddenly springs open as a 10 ft. tall horrifying spider lunges out towards whatever stepped into its trap.

A giant trapdoor spider may make one stabbing bite attack during the surprise round against a size Small or Medium target within 10 ft. of its hole. If this attack is successful it immediately backs into its tunnel to consume its prey. Re-entering the hole automatically causes carefully placed webs to trigger the trapdoor to close behind it, separating itself and its prey from any other creatures, allowing it to consume its prey safely.

Encounter Area

Encounter Options

Too Weak!

Add spiderlings in tunnel!

If you would like to increase the challenge level of this encounter a bit, add one or two spider swarms inside the tunnel. During the surprise round, while mommy is out getting their food, they are readying to move over whatever she brings back. When a victim is drug into the tunnel, the spiderlings immediately (as a readied action) swarm over it, causing a bit more to be concerned with.

Adding one spider swarm increases the CR of this encounter from 4 to 5 and the XP award changes from 1,200 to 1,600.

Adding two spider swarms increases the CR of this encounter to halfway between 5 and 6 and increases the XP award from 1,200 to 2,000.

Too Tough!

Add a giant wasp!

Giant wasps are natural hunters of trapdoor spiders. They fly about in search of tunnels and then simply chew through the trapdoor. Once through the door they sting the spider, inject it with eggs, then fly away. If you wish to offer your players a bit of an "escape valve" or rather, a way to dial back the threat level a bit, if the spider is having its way with a PC perhaps have a giant wasp be overheard buzzing nearby. The player's will likely react with some degree of nervousness, especially of the encounter is already going poorly. However, when the wasp arrives it zeros in on the tunnel, immediately begins chewing on the "soil" and then engages with the spider, possibly offering the trapped PC or his allies an opportunity to free him, especially of there is now a giant-sized hole in the trapdoor. If the PCs are foolish enough to attack the wasp though, this could quickly turn from an attempt to save their bacon to a TPK (total party kill.)

If you feel it necessary to reduce the challenge of this encounter by adding a giant wasp, reduce the overall CR by 1 and reduce the XP awarded from 1,200 to 800.

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