Spirit Ooze
Large natural animate (blind, ooze, undead)
Level 16 Elite Lurker XP 2800

Initiative +20        Senses Perception +10; blindsight 10
HP 166; Bloodied 83
AC 32; Fortitude 27, Reflex 32, Will 31
Immune disease, gaze, poison; Resist 10 necrotic, insubstantial
Saving Throws +2
Speed fly 6 (hover)
Action Points 1

(⚔) Spirit Sink (standard, at-will) ✦ Necrotic

Reach 2; +19 vs Fortitude; 3d6+5 necrotic damage, and the target is weakened (save ends). In addition, the spirit ooze gains phasing until the end of its next turn.

Split ( when first bloodied; encounter)

The spirit ooze splits into two Large individuals, the second one occupying a space adjacent to the original creature. Each of the two creatures has hit points equal to one-half the original's current hit points. Both creatures act on the original creature's initiative count. Effects applied to the original ooze do not apply to either of the individuals after the split occurs. A spirit ooze can't split if reduced to 0 hit points by the attack that bloodied it.
If out of combat for 5 minutes, the two halves combine back into one spirit ooze, which has hit points equal to the combined value of the two halves.

Combat Advantage

A spirit ooze deals 2d6 extra damage when it hits a target it has combat advantage against.

Phase Away (minor; while the spirit ooze has phasing; at-will)

The spirit ooze shifts up to 1 square.

Slippery Phasing (while the spirit ooze has phasing)

The spirit ooze gains a +2 bonus to AC and Reflex.

Alignment Unaligned        Languages -
Skills Stealth +21
Str 16 (+11)      Dex 26 (+16)      Wis 15 (+10)
Con 17 (+11)      Int 2 (+4)      Cha 11 (+8)

Published in Open Grave, page(s) 175, The Plane Below, page(s) 99.