Amorphous. The pudding can move through a space as narrow as 1 inch wide without squeezing.   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 fo metal that hits the ooze is destroyed after dealing damage.
The ooze can eat through 2-inch-thick, nonmagical metal in 1 round.   False Appearance. While the ooze remains motionless, it is indistinguishable from an oily pool or wet rock.