Pigmy rattlesnake
(Sistrus Miliarius)

The effect of this snake's venom is generally mild.  Symptoms are generally limited to local swelling and minor tissue damage.  Swelling often includes the entire extremity and limb.  Systematic effects are usually limited to nausea.   This author knows of no accounts of fatalities.  This snake is probably not capable of delivering a lethal bite without involving sensitive allergic reactions.