Centourax - twenty-foot long centipede

Cities are by far the safest place in my world, thousands of people come together in areas protected from the cold, undead and other threats. One of the side benefits is that there are lots of places where beasts can thrive - underneath the city is a very common one, and that's where the Centipede Maurax, or Centourax reside.

These are very long centipedes, (though classified as medium sized creatures) they usually find a place with water and start building tunnel complexes. If they grow large enough, the tunnels can be large enough for small, medium or sometimes even large creatures to walk thru them.

Centourax
Medium Abberation
AC 15 .(+5 natural)
Hit Points 2 HD (7 hp)
INIT -1
SPEED 30 ft, Run 50 ft, Tunnel 5 ft
Attack tentacle  +4 1d6 dmg
Fort +4 / Reflex +0 / Will +1
Dmg Reduction 1/2*
Skills: Perception +5, Stealth +8, Climb +16, Craft +2
Feat: Co-Ordinate, Fast Retreat
CMB +7, CMD +16 (fast centipede, foot long)
Environment: Underground
Alignment: - Neutral
Advancement HD 3-8 (Medium); 9-16 HD (Large)
Increase HD Dmg for every Advancement (1d8 @ 3-8; 1d10 @ 9-16)

Special Defenses: Centipede Maurax can be affected by mental, mind or control matter but the effect lasts no more than one minute.

Feat: Co-Ordinate: Gain +1 in craft skills for every 5 workers that work together on the same project.
Feat: Fast Retreat: Once a day a Centourax can do a straight run for three rounds to avoid potential danger

Twenty-foot long centipede, 50 plus small legs, around one foot tall and wide with eight inch maxilla (mouth tentacles), small but very sharp mandibles with black outer shell with yellow squares throughout it's skin.

They work in groups towards a common goal, most times they have no obvious leader just a shared consciousness that co-ordinates activity. They prefer eating meat as it helps them grow, but they can survive on grubs and mushrooms if it's easier to obtain.

Damage Reduction: 1 point,