Siege Monster. Double damage to objects and structures.

Spelljamming. When in the vacuum of space and away from any gravity well this creature can move 4 million mph. All crew members must agree for the Zwarth to begin Spelljamming.

Crewed Creature. The Zwarth can be piloted by 5-8 medium or smaller creatures who must use an action while within 5-ft. of the Zwarth to board it, once inside a creature sits on a special chair called a helm that allows that creature to control the Zwarth and see through its senses. A crew member inside the Zwarth can choose to close the entrance to the Zwarth at will. If a creature the Zwarth doesn't recognize attempts to sit in one of the helms, that will fail to benefit from using the helm. A creature can get up from a helm at any time at the beginning of their turn. All creatures inside the Zwarth have full cover from outside effects.

Master's Vitality. When a new crew is integrated into a Zwarth, increase the Zwarth's maximum hp by 1d12 for every player level all of the crew members have combined (If crew consists of PCs) or for every point all of the crew's CR combined. If a crew member dies, the Zwarth will loose the extra health granted by that crew member at dawn.

Immutable Form. The Zwarth is immune to any spell or effect that would alter its form.

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

Crew Multiaction. While the crew of the Zwarth man the helms they forgo their ordinary actions and may each channel an action or a single bonus action through the Zwarth using its statistics but may employ any ability that that crew member might posses. Using the attack action this way can only be used to deal one weapon attack only. Its movement allowance is divided equally among the crew.

Spell Projection. If a crew member casts a spell on their turn while helming the Zwarth, that spell is cast as if the Zwarth were casing it and if the spell deals damage, that damage is multiplied by 10. The Zwarth can use itself as an arcane focus.

Long sword. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 22 (3d8 + 9) slashing damage. or 25 (3d10 + 9) slashing damage if used with two hands.

While it has a crew, the Zwarth will always take an attack of opportunity against a hostile enemy if it becomes available.