Transparent. Even when the jellyfish is in plain sight, it takes a successful DC 12 Wisdom (Perception) check to spot the creature if it has neither moved nor attacked. A target that tries to enter the jellyfish's space while unaware of the creature takes 4 (1d4+2) lightning damage and is surprised by the creature.
Lightning Susceptibility. If the jellyfish takes lightning damage its speed becomes 0 until the end of its next turn.
Amorphous. The jellyfish can move through a space as narrow as 1 inch wide without squeezing.
Tendrils. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) lightning damage. A Medium or smaller target is stunned until the start of its next turn.
Description
A jellyfish is a free-swimming marine animal consisting of a gelatinous umbrella-shaped bell and trailing tentacles. Some types of jellyfish found in the oceans of Toril aren't translucent, and some deal cold, force, poison, or necrotic damage instead of lightning. Some are Tiny with 2 hit points each. A swarm of jellyfish is called a bloom.