Shadowsponge [Air Stealer]

Every spacefarer dreads these things. A shadowsponge is a grayish lump with hundreds of rubbery, branching air sacs sprouting from its core, dotted with small, sharp eyes and sensory patches. It drifts through the void until it detects an atmosphere, which it can 'smell' up to three miles away, then charges in to drink the air. Its flesh cannot be eaten. Fire and lightning hurt it normally but set it smoldering, releasing a choking smoke that swells to a 30-foot sphere for 2-5 turns, limiting sight to 4 feet and fouling any clean air inside it.

A sponge in an atmosphere wheels and dives without pause, absorbing air, and anything nearby may be rammed or engulfed. A ram needs an attack roll, deals 1 point of damage, and knocks the target flat unless it passes a Strength check (carried items save vs. fall). An engulfing attack wraps the victim for 1 point, then 1-4 points of crushing each round after. The trapped victim automatically hits the sponge with any piercing or slashing weapon already in hand, but cannot cast spells, pull out other items, or swing blunt weapons. Sponges over 40 hp can hold two man-sized beings; smaller ones hold one.

Because the sponge is porous and full of air, prisoners do not suffocate, but every other round each must save vs. breath weapon or suffer the effects of whatever harmful gases the creature soaked up before. Attacks on the sponge can spill onto a prisoner: the victim saves against that attack form (vs. breath weapon for physical blows) or takes one quarter of the damage dealt, rounded down but at least 1. Killing the sponge, or dealing it more than 20 damage in one round, makes it spasm and spit out its captives, who still suffer the damage from the attacks that freed them.

Heat alone, without flame, does not hurt a shadowsponge; it heals or adds hit points equal to the damage it would have caused. Flame works normally.

Only semi-intelligent, sponges flock by instinct toward small atmospheres in the void, shunning the large, stable air of whole worlds. They never collide or fight with each other, can merge their own scattered pieces or join another sponge into a bigger one, and have no breeding or families. Some sages think they are a stage in the life of a more advanced fungus: once a sponge absorbs the nutrients it needs, it dives into a world's sky, falls, and breaks into spores that start a new form of life. An ancient sage-wizard warns that much of this cycle remains unproven.

They live on nutrients drawn from gases, plus light and weak electrical and heat energy, and belong to no food chain. Alchemists and researchers have found no use for their tissue. One doubtful result: weak electricity from a shocking grasp spell or certain gnomish energy devices makes a sponge give up 25% of its stored air.

Desperate crews sometimes cage sponges in a wreck or other sturdy container and drag them through planetoid atmospheres or skim a world's sky, creating a portable air supply so a ship too small can carry too many people too far. Others aim a caged sponge at an enemy base, planetoid, ship or elven armada craft to steal its air. Penned or forced into planetary air, sponges do store breathable atmosphere, but the strain kills them: each must save vs. petrification every day of confinement or die at once, poisoning the air around it. A dead sponge fouls 40 tons of air, and once a ship's whole supply is fouled, each further 40-ton fouling turns 40 tons of foul air deadly. Many explorers have cut loose barges full of dead sponges and limped on with too little air.

Some small, dark sponges lead others on long journeys and round them into groups. These herd clouds have 8+8 Hit Dice, Very intelligence (11-12), Champion morale (15-16), and are worth 3,000 XP. They store electric charge and in each 144-turn 'day' can unleash a single 9d6 chain lightning plus a pair of forked 6d6 bolts; brushing against or flying through a charged cloud is safe unless it chooses to discharge. Some sages think herd cloud essence could shield against or produce electrical magic, but every experiment so far has ended in shocking disaster.