serpent (n.) Look up serpent at Dictionary.com
c.1300, "limbless reptile," also "tempter in Gen. iii:1-5," from Old French sarpent, from Latin serpentem (nominative serpens) "snake," from present participle of serpere "to creep," from PIE *serp- (cf. Sanskrit sarpati "creeps," sarpah "serpent;" Greek herpein "to creep," herpeton "serpent;" Albanian garper "serpent").