Amorphous. The ooze can move through a space as narrow as 1 inch wide without squeezing.

False Appearance. While the ooze remains motionless, it is indistinguishable from a puddle of water.

Attach. When the ooze hits an enemy with its pseudopod attack, it initiates a grapple. While the ooze is grappling an enemy in this way it cannot attack but can use its action to deal 2d6 acid damage to the grappled enemy and if the target is wearing nonmagical metal armor, its armor is partly corroded and takes a permanent and cumulative -1 penalty to the AC it offers. The armor is destroyed if the penalty reduces its AC to 10.

The ooze has advantage on opposed strength checks against grappled foes.

Corrode Metal. Any nonmagical weapon made of metal that hits the ooze corrodes. After dealing damage, the weapon takes a permanent and cumulative -1 penalty to damage rolls. If its penalty drops to -5, the weapon is destroyed. Nonmagical ammunition made of metal that hits the ooze is destroyed after dealing damage.

The ooze can eat through 2-inch-thick, nonmagical metal in 1 round.

Pseudopod. Melee Weapon Attack: +3 to hit, reach 5 ft., one target.
Hit: 3 (1d4 + 1) bludgeoning damage plus 3 (1d4) acid damage, and if the target is wearing nonmagical metal armor, its armor is partly corroded and takes a permanent and cumulative -1 penalty to the AC it offers. The armor is destroyed if the penalty reduces its AC to 10.