Diseased Bite

Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 5 (1d4 + 3) piercing damage plus 10 (3d6) necrotic damage, and the rotsam attaches to the target. While attached, the rotsam doesn't attack. Instead, at the start of each of the rotsam's turns, the target takes 10 (3d6) necrotic damage. If a creature ends its turn with a rotsam attached to it, the creature must succeed on a DC 12 Constitution saving throw or contract a disease (see the Bog Rot trait). The rotsam can detach itself by spending 5 feet of its movement. It does so after the target contracts its disease or the target dies. A creature, including the target, can take its action to detach the rotsam by succeeding on a DC 12 Strength check.