• Able to cast limited wish, polymorph any object, summon swarm, and sympathy
  • Feat: Heighten Spell
  • Alignment: evil
  • Must perform the transformation ritual. This takes a full day and requires 10000gp of rare reagents. At sundown, the caster kills himself. Provided the body is not disturbed, it rises at the next dawn as a mass of worms.

{table=head]Level|BAB|Fort Save|Ref Save|Will Save|Special|Spellcasting
1st|0|0|0|2|Aberration conversion, immunities, discorporate|
2nd|1|0|0|3|Engulf 5, Frightful Presence (HD/4+Cha)|+1 level of existing arcane class
3rd|2|1|1|3|Awareness +1, Blindsight 15, Spell Resistance (HD)|+1 level of existing arcane class
4th|3|1|1|4|Vermin Messenger, Vermin Trance, Summon Swarm of Vermin|+1 level of existing arcane class
5th|3|1|1|4|Engulf 25|+1 level of existing arcane class
6th|4|2|2|5|Awareness +5, Blindsight 75|+1 level of existing arcane class
7th|5|2|2|5|Vermin Growth, Colossal Vermin, Insect Plague, Frightful Presence (HD/2+Cha), Spell Resistance (HD+13)|
8th|6|2|2|6|Engulf 100|+1 level of existing arcane class
9th|6|3|3|6|Awareness +20, Blindsight 300|+1 level of existing arcane class
10th|7|3|3|7|Vermin Shapes, Creeping Doom|+1 level of existing arcane class[/table]
HD: d8
Skills: 2+int
Class Skills: Concentration, Craft (any), Hide, Knowledge(any), Listen, Move Silently, Spellcraft, Survival

Most of the table should be self-explanatory (at least along with the monster description.

Aberration Conversion: Increase all previous hit dice to d8s with 3/4 BAB and good will saves (if they were better than this, leave them). Type becomes aberration.

Awareness: This is the benefit of thousands of little sense organs. Add this value to AC, Hide, Survival, Listen, and Move Silently checks.