just remember, you asked for it!
SKUZ
Medium-Size Undead
Hit Dice: 11d12+3 (74 hp)
Initiative: +6 (+2 Dex, +4 Improved Initiative)
Speed: 5 ft, swim 40 ft
AC: 20 (+2 Dex, +8 natural)
Attacks: 2 slams +12 melee
Damage: Slam 1d8+6 plus energy drain
Face/Reach: 5 ft by 5 ft/5 ft
Special Attacks: Energy drain, spell-like abilities, create spawn
Special Qualities: Undead, damage reduction 15/+2, SR 16, alter self, blindsight, resistances, vulnerabilities, turn resistance +2, unnatural aura
Saves: Fort +3, Ref +5, Will +10
Abilities: Str 22, Dex 14, Con —, Int 16, Wis 16, Cha 14
Skills: Concentration +13, Hide +12, Listen +12, Move Silently +12, Search +12, Swim +24
Feats: Alertness, Dodge, Combat Reflexes, Improved Initiative, Toughness, Weapon Focus (slam)
Climate/Terrain: Warm and temperate aquatic
Organization: Solitary or pack (2-5)
Challenge Rating: 9
Treasure: Standard
Alignment: Always chaotic evil
Advancement: 12-22 HD (Medium-size); 23-33 HD (Large)
Skuz are ooze-like undead creatures found in stagnant ponds and lakes. Its natural form is that of a slimy green coating on the water, similar to algae. When prey comes near, it rises from the water and appears as an amorphous column of slime.
COMBAT
A skuz attacks by lashing out with a slimy pseudopod formed from its semi-liquid body. When a humanoid victim is sufficiently weakened in this way, the skuz pulls it into the water and attempts to drown it.
Energy Drain (Su): Living creatures hit by a skuz's slam attack receive one negative level. The Fortitude save to remove the negative level has a DC of 17.
Create Spawn (Su): Any humanoid drowned by a skuz becomes a skuz in 1d4 rounds. Humanoids who are killed by a skuz, but not drowned, do not become skuz. Spawn are not obligated to remain with their creator, but often do just to increase the hunting capability of the skuz in the area. However, if a pond or lake becomes too crowded, some opt to leave, crawling to another body of water.
Spell-like abilities: 2/day—animate dead, suggestion, and transmute rock to mud. These abilities are as the spells cast by an 11th-level sorcerer (save DC 12 + spell level).
Undead: Immune to mind-influencing effects, poison, sleep, paralysis, stunning, and disease. Not subject to critical hits, subdual damage, ability damage, energy drain, or death from massive damage.
Alter Self (Su): At will, a skuz can alter its form to appear as any humanoid or other form, most often appearing as a human child. It uses this tactic to appear to be drowning in order to lure prey to its death. This ability otherwise duplicates the spell of the same name.
Blindsight (Ex): As an ooze-like creature, the skuz has no visual organs, but its whole body acts as a sensory organ, allowing it to perceive its environment to a range of 60 feet.
Resistances (Ex): Skuz are immune to all fire effects. Because of its malleable body, it takes only half damage from edged weapons.
Vulnerabilities (Ex): The lower water version of the control water spell deals 2d10 points of damage to a skuz, and raise dead instantly kills it. They do not leave their pond or lake if turned, but they attempt to avoid the offending cleric.
Unnatural Aura (Su): Both wild and domesticated animals can sense the unnatural presence of a skuz, even from within a body of water, at a distance of 20 feet. They will not willingly approach nearer than that and panic if forced to do so; they remain panicked as long as they are within that range.
The Skuz first appeared in MC11, Forgotten Realms Monstrous Compendium Appendix II (1991, David "Zeb" Cook).
One of the first things I noticed about this guy is that I should have given him the amorphous quality, a la the gibbering mouther. Easily fixed!
Another thing we can do is give it DR/blunt and immunity to fire to remove that weak “resistances” thing. We should probably also spruce up the “vulnerabilities” entry.