A poisonous snake. Several species of snakes are called vipers, and the various words used in the Bible for them probably do not designate specific types. Some scholars take the Old Testament references to refer to the Echis Colorata. Jesus spoke of the wicked religious leaders as vipers (Matthew 3:7) because of their venomous attacks on Him and their evil character in leading the people astray. Paul was bitten by a viper (Acts 28:3) but suffered no ill effect from it.
These dictionary topics are from the Holman Bible Dictionary, published by Broadman & Holman, 1991. All rights reserved. Used by permission of Broadman & Holman.
Butler, Trent C. Editor.. "Entry for 'VIPER'". "Holman Bible Dictionary".