Mudblood

Mudblood (minor) by Stone Gargoyle

"Blood is thicker than water."

The character has thick, syrupy blood that quickly clots to prevent bleeding. Vital organs clot quickly as well, so a strike to the heart is not fatal and the character will only take half damage to HP.
Any piercing weapon passing through the character will get stuck and held, requiring a PS greater than the character's PE score to withdraw it, and the weapon will be covered in the syrupy blood, making it only do half its normal damage until the blood can be cleaned off using solvent or harsh cleansers. Note that this also makes surgery on the character nearly impossible, but severed limbs will be able to be reattached more easily (+10% to medical skill roll to do so).