פֶּתֶן (pethenpeh'-thennoun|masculineserpent)
[Heb] פֶּתֶן ETCBC: פֶּתֶן‎ (subs|cobra) OSHL: q.ed.ab TWOT: 1858a GK: H7352 Greek: ἀσπίς, βασιλεύς, δράκων
Derivation: from an unused root meaning to twist;
Strong's: an asp (from its contortions)
KJV: adder.