Shifting Jelly (5e Creature)
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Medium ooze (shapechanger), chaotic evil
Skills Deception +5, Perception +3, Stealth +6
Shapechanger. The jelly can use its action to polymorph into a Small or Medium ooze-humanoid hybrid or into a Small or Medium humanoid, or back into its true form, which is an ooze. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.
Amorphous (Ooze or Hybrid Form Only). The jelly can move through a space as narrow as 1 inch wide without squeezing.
Spider Climb (Ooze Form Only). The jelly can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Multiattack. In ooze form, the jelly makes two pseudopod attacks. In humanoid form, it makes two attacks with its longsword. In hybrid form, it can attack like an ooze or a humanoid. In hybrid form, it can substitute one of its other attacks to make an attack with its claws.
Pseudopod (Ooze or Hybrid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 3) bludgeoning damage, plus 7 (2d6) acid damage.
Claw (Hybrid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) slashing damage, and if the target is a creature, it must succeed on a DC 15 Constitution saving throw or be poisoned for 1 minute. An affected creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Longsword (Humanoid or Hybrid Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage, or 8 (1d10 + 3) slashing damage if used in two hands.
Vicious oozes that seem to constantly change colours, shifting jellies are feared for their unnatural cunning and their ability to polymorph into humanoid forms or hideous ooze-humanoid hybrids with sharp claws.
Ooze Nature. A shifting jelly doesn't require sleep.