Vipers carry solenoglyphous fangs, hollow teeth mounted on a rotating maxilla that folds back along the palate when the mouth shuts. That hinge is what allows a fang far longer than the gape would otherwise permit, and in a large Gaboon viper it reaches roughly four to five centimetres, the greatest recorded in any snake.
Long fangs deliver venom deep into muscle rather than into skin, and the species also produces a large volume of it. The combination matters more than raw toxicity: the venom is not exceptionally potent by weight, but the delivered dose can be very large.
The temperament is the opposite of the reputation such an animal invites. Gaboon vipers are notably placid, relying on a disruptive pattern that renders them nearly invisible in leaf litter, and most bites follow someone stepping on or picking up a motionless snake. Strike speed is often described in dramatic terms, though careful measurements of viper strikes are relatively recent and few cover this species.