At this moment Abyssal viper is one of the two worst Beasts in game (second one is Fire fox). But if Fire fox can at least inflict 9-12 damage after Wildfire gem, Abyssal viper is nothing but a deadweight in Beast decks.
It can be useful in resource stealing/breaking deck, but there is no synergy between such decks and Beast keyword. I'd like to see this card being reworked into something useful either for Beast decks (damage, Quick keyword) or resource breaking.