Arachnid Terror

Defenses

Saving Throws: Dexterity +5, Constitution +4

Damage vulnerability. Radiant damage and Physical damage from weapons coated with or made of silver

Damage resistance. Psychic damage, simple Physical damage, and Necrotic damage.

Damage immunity. Poison damage.

Condition immunity. Bleeding and Exhaustion.

Characteristics

Web Walk. The Arachnid Terror ignores movement restrictions caused by webs.

Descycle. When reduced to 0 hit points, the Arachnid Terror must make a Constitution check with a DC equal to 10 or half the damage taken, whichever is higher. This effect isn't triggered if it's destroyed as a result of sources that directly interact with the destruction of undead, such as the Spiritual Rite Acolyte's "Liturgy: Destroy Undead."

Spider Climb. The Arachnid Terror can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Mist Wraith. This undead is native to the Black Mist and is positively affected by it.

Web Sense. While in contact with a web, the Arachnid Terror knows the exact location of any other creature in contact with the same web.

Final Breath (1 use). Upon being reduced to 0 hit points, the Arachnid Terror can use its reaction to deny its death and rise again, having its maximum hit points reduced by an amount of d12 between 1 and 32 of its choice, generating a necrotic explosion within a 15-foot radius around it. Creatures in the area make a DC 13 Constitution saving throw and, on a failure, take 1d8 Necrotic damage for each d12 of hit points reduced from the Arachnid Terror and become Paralyzed until the end of their next turns. On a success, the creature takes only half the damage and doesn't become Paralyzed.

Attacks

Multiattack. The Arachnid Terror can make 3 Legs attacks and 1 Bite attack in the same turn using only one action.

Bite. Melee Natural Weapon Attack, +8 to hit, 10 ft. reach, one target. On a hit, deals 30 (4d12+4) Piercing damage + 13 (2d12) Necrotic damage.

Legs. Melee Natural Weapon Attack, +9 to hit, 10 ft. reach, one target. On a hit, deals 19 (3d12+5) Slashing damage + 13 (2d12) Necrotic damage.

Web (Recharge 4-6). Ranged Natural Weapon Attack, +9 to hit, 40/80 ft. range, one target. On a hit, the target becomes Restrained by webs. The target can use an action to make a DC 15 Strength check, escaping the web and ending the condition on a success. The web can also be attacked and destroyed (AC 10; 5 hit points; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).

Epic Actions

The Arachnid Terror has 4 charges of epic actions, and can spend one of these charges to act. Only one action can be used at a time, at the end of another creature's turn. At the start of the Arachnid Terror's turn, the number of charges returns to 4

The Arachnid Terror can take an action and restore its reaction (if spent)

The Arachnid Terror can spend all or the rest of its movement

The Arachnid Terror can repeat a saving throw against an effect affecting it

Cost. When the Arachnid Terror repeats its saving throw this way, it loses 6 hit points.

Epic Resistance

Resilience Points: 141 When the Arachnid Terror would fail a saving throw against any effect, it can spend 12 Resilience points to succeed instead. Additionally, the Arachnid Terror can use the effect below:

Determination: When a target makes a saving throw to resist an effect, the Arachnid Terror can spend 3 Resilience points to grant it advantage on the roll.