Adder in Easton's Bible Dictionary

(Ps. 140:3; Rom. 3:13, "asp") is the rendering of, (1.) Akshub ("coiling" or "lying in wait"), properly an asp or viper, found only in this passage. (2.) Pethen ("twisting"), a viper or venomous serpent identified with the cobra (Naja haje) (Ps. 58:4; 91:13); elsewhere "asp." (3.) Tziphoni ("hissing") (Prov. 23:32); elsewhere rendered "cockatrice," Isa. 11:8; 14:29; 59:5; Jer. 8:17, as it is here in the margin of the Authorized Version. The Revised Version has "basilisk." This may have been the yellow viper, the Daboia xanthina, the largest and most dangerous of the vipers of Israel. (4.) Shephiphon ("creeping"), occurring only in Gen. 49:17, the small speckled venomous snake, the "horned snake," or cerastes. Dan is compared to this serpent, which springs from its hiding-place on the passer-by.