horned asp vs horned viper

horned asp and horned viper both are nouns.

Word	Noun	Adjective	Verb	Adverb
horned asp	Yes	No	No	No
horned viper	Yes	No	No	No

As nouns, horned asp and horned viper are synonyms defined as:

horned asp and horned viper: highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye

Other synonyms of horned asp include cerastes, Cerastes cornutus, sand viper.

horned asp (noun)	horned viper (noun)
highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye	highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye