This is the Disadvantage I am using, from The Master List of Limitations.
Physical Limit: Body of (Unusual Substance) (All the Time, Slightly Impairing)
This character's body is made of some unusual, possibly inorganic substance. Examples would include a character whose body is made of steel, or wood, or quartz crystal. The specific effects of this Disadvantage should be determined by the GM based on the material in question. For example, a character's whose body is made of steel might not be as limber and flexible as normal. His sense of touch might also be lessened, and he would have less sense of temperature unless near an extreme (such as boiling hot or freezing). Also, he would weigh much more than normal, and has to take this into account when using furniture, getting into a vehicle, etc. Depending upon the specifics, other Physical Limitations would also be appropriate (like for excess weight or having reduced tactile sensations).
Was hoping you fine ladies and gentleman could assist me with ideas of what the effects of this Physical Limitation should be. I already have Distinct Feature and a Physical Limitation for Increased Weight in addition to this disad.
Thanks in advance for any help/suggestions.