Article:
D&D 4th ed: Creature Features (Part 2)

Continuing on with the Creature Features tables, here are some finer features that can be added to your unique creations, or added to existing monsters to make them a little bit more disconcerting for your players.

If a Purple Dragon has a duck bill and emits weird vapors, what else can it do that your players don't know about?

RANDOM CREATURE FEATURES TABLE
01-02 Armor Plated; +3 natural AC bonus, add 10 to Hit Points.
03-04 Covered in fungus; Symbiotic fungus provides camouflage, protection and nourishment.
05-06 Dome Shaped; like a crab, with it's body flatter underneath and rounder on top. Limbs are arranged around it.
07-08 Double Headed; 2 heads on 1 torso, +2 to perception.
09-10 Doughnut Shaped.
01-12 Elastic Bones; Only takes half damage from any kinetic attacks (falls, punches, explosions, etc).
13-14 Emits Vapors; grants concealment if it doesn't move for a few rounds and there is little or no wind.
15-16 Extra limbs; Roll 1d6 (1-3 Arm, 4-5 Leg, 6 Head).
17 Fat; life form appears overweight, however it may be pure muscle.
18-19 Featureless; a totally blank face and body. No eyes, ears, nipples, etc. This life form's senses must work in a totally different manner to the norm. This skin is also totally smooth.
20-21 Flat Billed; platypus type beak.
22-23 Frilled; lizard type vane around the neck.
24-25 Headless; Sensory organs are located on the main torso.
26-28 Horned; Up to 1d4 horns on head (basic gore attack).
29 Hourglass Shaped; unusual body shape.
30 Huge Jaw; neck length.
31 Jointed Spines; The creature has long spines (sturdy) with joints like knees or elbows it can bend and feel like limbs/fingers. The spines may be used as locomotion or for display.