Arcane Ooze

The creature resembles a fluid mass of green protoplasm. Within its immense bulk, glowing veins throb and pulse with eldritch light.

Created in ancient times, arcane oozes have long since outlived their original purpose and their long-forgotten creators. The bizarre creatures have a strange affinity for arcane magic. Immune to most arcane magic, arcane oozes drain arcane energy from nearby spellcasters. Some speculate that these oozes were created to combat a rival group of arcane spellcasters, but scant evidence backs any such conclusion. Others suggest arcane oozes arose as a natural response to some cataclysmic event caused by arcane magic. Adherents of these later theories claim that one day arcane oozes will drown out all arcane magic in the world.

An arcane ooze measures 15 feet across and 3 feet thick. It weighs as much as 20,000 pounds.

Combat

An arcane ooze attacks by grabbing and squeezing its prey. It moves instinctively toward the nearest creature capable of casting arcane spells. It can only detect such creatures (or any creature) if they are within 60 feet. If attacked by creatures that it cannot detect (because they are too far away), the ooze instinctively retreats. An arcane ooze can travel easily on vertical surfaces, and it lurks on such surfaces, attempting to catch prey by surprise.

Acid (Ex): An arcane ooze secretes a digestive acid that dissolves only flesh. Any successful hit in melee combat or a constrict attack by the creature deals an extra 2d6 points of acid damage.

Constrict (Ex): An arcane ooze deals automatic slam damage and acid damage with a successful grapple check.

Improved Grab (Ex): To use this ability, an arcane ooze must hit with its slam attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Spell Siphon (Su): An arcane ooze exerts a strange pull on arcane spell energy. Any time an arcane spellcaster begins his turn within 60 feet of an arcane ooze, he must make a DC 25 Fortitude save or lose a random spell of the highest spell level that he has available. For every spell lost by a victim in this manner, the arcane ooze gains temporary hit points equal to 5 × the level of the lost spell. These temporary hit points are lost after 1 hour.

Line of effect between the spellcaster and the arcane ooze is necessary in order for this ability to work. The save DC is Constitution-based.

Immunity to Magic (Ex): An arcane ooze is immune to any spell or spell-like ability that allows spell resistance. In addition, certain spells and effects function differently against the creature, as noted below.

A magical attack that deals electricity damage increases an arcane ooze’s speed as if it had been affected by the haste spell for 3 rounds.

A magical attack that deals acid damage heals an arcane ooze of an amount of damage equal to half the acid damage that the spell would normally have caused.

Skills: An arcane ooze has a +8 racial bonus on Climb checks and can always choose to take 10 on a Climb check, even if rushed or threatened.

Arcane Oozes in Eberron

Arcane oozes are found in places where arcane spellcasters dwell, or in abandoned demesnes where wizards once held sway. They are encountered with alarming regularity in the depths of Sharn, the City of Towers.

Source: Monster Manual III, page 9.