Walking Limb (5e Creature)
From D&D Wiki
Small monstrosity, chaotic neutral
Saving Throws Dex +5, Cha +5
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage.
Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) bludgeoning damage.
Choke. Melee Weapon Attack: +5 to hit, reach 15 ft., one target. Hit: The target is grappled (escape DC 11). Until this grapple ends, the limb can't make choke attacks against other creatures.
A walking limb can either be part of one's arm or leg that was infected and has a monster growing from just below the elbow or knee. The small monster has a giant vertical mouth with small, sharp teeth. Small tentacles surround it's mouth and move unpredictably. The blood inside the monster runs green, when the walking limb dies, the parasite inside can escape, if the parasite itself isn't killed it can go on to infect another limb, causing it to start walking.