Added a special quality (actually a limitation), and a new paragraph to Strangle (which also is a nerf). Both are reproduced below for you convenience.
Soft(Ex): An unarmed slithering spinal cord is utterly incapable of causing hitpoint damage per se (dropping hit-points due to lack of air are another matter entirely). It could be ordered to trigger a trap, or pick up a weapon in one end (but even then it would be non-proficient with it), but its only native attack that involves an attack roll is its paralysis touch. Armed or not, a slithering spinal cord is too clumsy with weapons to perform a coup-de-grace.
Sinister spinal cords wrapped around necks count as flat footed to attacks if the following conditions are met:
- Said attack are made with daggers, scalpels, scissors (which do not count as improvised weapons in this case), and similar bladed weapons and tools.
- The attacker must be able to see the sinister spinal cord, which does NOT generally include the person whose neck they are wrapped around unless a mirror is used in which case a flat -1 to hit against the flat-footed sinister spinal cord is imposed.
EDIT: Added CR for Gargantuan and Colossal ones based on Vorpal Tribble's formula. Counted Undead as being worth 4 points (IE +1.333 CR). I hear it doesn't work very well for non-"Hulk Smash!" monsters but these are SORTA that.