An upcoming boss fight sees the PC fight a darkfathom (see below), a homebrew creature based on this miniature. The encounter will take place in the darkfathom's underwater lair, a large chamber containing a few statues that the darkfathom can command to become animate if need be. Its lair is entered through a labyrinth of smaller chambers into which the PCs can retreat. The darkfathom has been scrying on the PCs for some time and knows their strengths and weaknesses.

The ten PCs are a duskblade, knight, rogue, sorcerer, and warlock that are each level 6, and a bard, dragon shaman, fighter, ranger, and werebear that are each level 7. The PCs will have magically gained freedom of movement and water breathing effects as well as swim speeds.

The Darkfathom

Gargantuan Outsider (augmented dragon)

Hit Dice: 22d12+154 (297 hp)
Initiative: +4 (−1 Dex)
Speed: 60 ft., swim 60 ft.
AC: 28 (−2 size +21 natural −1 Dex), flat-footed 28, touch 9
Base Attack/Grapple: +22/+42
Attack: Bite +28 (4d8+12)
Full Attack: Bite +28 (4d8+12), tail slap +28 (2d8+12), 2 claws +28 (2d8+4), 2 minor tails +28 (2d8+4), 2 major tails +28 (2d8+4)
Space/Reach: 20 ft./15 ft. (20 ft. bite)
Special Attacks: breath weapon, crush, spell-like abilities, spells, tail sweep
Special Qualities: blindsense 60 ft., darkvision 120 ft., DR 10/magic, frightful presence, immunity to sleep effects, immunity to paralysis effects, immunity to acid, keen senses, SR 21
Saves: Fort +21, Ref +12, Will +17
Abilities: Str 27, Dex 8, Con 27, Int 14, Wis 15, Cha 14
Skills: 200 skill points include 25 ranks in the skills Hide, Move Silently, and Swim, and 12 ranks each in the skills Diplomacy, Intimidate, Knowledge (arcana), Knowledge (the planes), and Sense Motive
Feats: Darkfathom Tail [see below], Multiattack (MM 304), Improved Multiattack (Dungeon #109 49), Iron Will (PH 97), Quicken Spell (PH 98), Rapid Breath (SS 39), Shape Breath (Dr 73), World Weary (Dragon #319 61)
Challenge Rating: 16?
Alignment: Chaotic Evil

Spells Known (6/7/5; CL 5; base save DC = 12 + spell level): 0—detect magic, daze, light, mage hand, ray of frost, read magic; 1st—color spray, magic missile, protection from good, shocking grasp; 2nd—pressure sphere, resist energy.

Breath Weapon (Su): It can every 1d4 rounds take a standard action to use its breath weapon. Creatures in a 120-ft. line make Ref saves (DC 29). Failure means that the creature is dealt 14d4 points of cold damage while success means that the creature's dealt half damage. It can instead every 1d4+1 rounds use its breath weapon as a 60-ft. cone.

Crush (Ex): It can take a standard action while jumping or flying to land. Medium or littler creatures caught in its space make Ref saving throws (DC 29). Failure means that until it ceases to occupy the creature's space, the creature is pinned and dealt 4d6+12 budgeoning damage each round.

Frightful Presence (Ex): When it attacks, charges, or swims overhead, creatures within a 210-ft. radius that have fewer than 22 HD make Will saves (DC 23). Failure by a creature that possesses 4 HD or less means that the creature for 4d6 rounds is panicked. Failure by a creature that possesses more than 4 HD means that the for 4d6 rounds the creature is shaken. Success means that for 24 hours the creature is immune to its frightful presence.

Keen Senses (Ex): It sees four times as well a human in shadowy illumination and twice as well in normal light.

Spell-like Abilities: 1/day—corrupt water, darkness.

Tail Sweep (Ex): It can take a standard action to make a tail sweep. Small or littler creatures within a 30-ft. half-circle extending from an intersection on the edge of its space in any direction make Ref saves (DC 29). Failure means that the creature's dealt 2d6+12 points of damage while success means that the creature's dealt half damage.

Note: The feat Darkfathom Tail gives it 1 extra tail with which it can make additional tail attacks as per the stat block.

  • \$\begingroup\$ Your introduction says the creature is Colossal, the statblock says the creature is Gargantuan. Also, it is very difficult to judge the capabilities of the party by their class and level alone—I mean, this thing has SR 21, does the sorcerer have SR: No spells that are useful here? He should, but if he doesn’t he’s going to be doing nothing 70% of the time. Likewise, that attack bonus probably means any investment in AC is going to be completely wasted for these characters—it’s going to hit anyway. Etc. \$\endgroup\$ – KRyan Mar 6 '18 at 14:15
  • \$\begingroup\$ @KRyan woops, sorry on the size thing... i was actually just remarking that the miniature was really big adn forgot colossal was an actual size... i have updated. And yes the sorcerror has SR no spells on hand. I agree it is hard to judge this based on level alone, I might be able to get all the players to give me their character sheets and upload them for review, but i fear that would take too much time for people to go through. Is there some more generic info that you think would be helpful? \$\endgroup\$ – Critical Crafting Mar 6 '18 at 14:27
  • \$\begingroup\$ To be honest, I have no idea. I agree, going through all their character sheets seems like too much work for a Stack question—for me, personally, anyway. But without doing it, the question can’t be answered. I don’t think there is necessarily any kind of cut off on questions where something is too hard—so I think you’re welcome to ask. I just don’t know that anyone is going to want to really do a good job answering it. Particularly in the timeframe where you want to run this encounter sometime in the near future. \$\endgroup\$ – KRyan Mar 6 '18 at 14:31
  • \$\begingroup\$ Under what circumstances the creature be encountered? What does the creature know about his foes? How much time will the creature have to prepare? Does the creature have any treasure that it can use in its defense? Who is the 10th PC‽ \$\endgroup\$ – Hey I Can Chan Mar 6 '18 at 15:22
  • \$\begingroup\$ @HeyICanChan The creature will be encountered underwater in his lair along with some statues that can be converted to golems to protect him (if needed), there is a labyrinth of smaller chambers the party can retreat to that the darkfathom will need to smash to reach them. The darkfathom knows ALOT about the PC's as he has been scrying them for some time. The 10th PC is a fighter (i forgot him) I updated :) \$\endgroup\$ – Critical Crafting Mar 6 '18 at 15:50