Vile Blood. When the wyrm reaches 0 hit points, it explodes in a gout of acid. Each creature within 5 feet of the wyrm must succeed on a DC 14 Dexterity saving throw or take 2d6 acid damage. The acidic blood of the wyrm can be salvaged in a glass jar or vial, conferring the same properties as a vial of acid.
Multiattack. If the wyrm successfully hits a creature with a Bite attack, it can attempt to Infest that creature.
Bite. Melee Weapon Attack: +0 to hit, reach 5 ft., one target. Hit: 1 piercing damage.
Infest. The wyrm attempts to burrow inside a humanoid creature. The creature must succeed on a DC 14 Constitution saving throw or become infested. The creature may attempt this Constitution saving throw again at the beginning of each of its turns up to its Constitution modifier (minimum of 1), after which point it takes on the statistics of an infested crew member and becomes an NPC under the DM's control. The mechanics by which an infested crew member can be released from the control of the wyrm is up to the DM's decision.
Description
The wyrm is a mysterious parasitic space creature capable of infesting humanoids and controlling them from the inside. While infested, the humanoid has no will of its own, following the orders of the wyrm and sometimes contorting into awful shapes to gain a tactical advantage in battle.