Dragonbite vipers are first mentioned in the Scorpion Den, where it was said one had been spotted near an orphanage, although it was a false story made up by Addax to distract Thorn, so he could bring Sunny to Burn and trade her for a place in Burn's army so he could go back to his family. He took Six-claws' daughter, Ostrich, and threatened to kill her if Sunny didn't go with him to Burn. Qibli explained to Sunny what it was shortly before she was kidnapped and taken to Burn's stronghold.
The viper was first seen when Burn opened the box Blister sent to her when the three sisters met outside of the stronghold. She recognized the hissing and killed the snake easily. However, Blister had sent a second snake as well, which sprang out and bit Burn's ankle, killing her. The first viper then tried to attack Sunny, but Clay pushed her and the rest of the dragonets out of the way and got bitten instead; however, he was saved by Peril, who burned out the venom before it could spread to his heart. Peril then killed the viper by stepping on it and burning it.
Dragonbite vipers are one of the most feared animals in Pyrrhia because, as their name implies, they are the only known snake that can kill a dragon with one bite. This was proven at the end of The Brightest Night, where a bite to the foot from one killed Burn in a matter of minutes.
A dragonbite viper's bite turns black and is at first the pattern of a starburst, and can be seen spreading through a victim's body. When it comes in contact with dragon flesh, the dragon is seized with spasms, convulsions, and terrible agony as well.
- It is possible that dragonbite vipers are more aggressive than normal snakes. As one of the vipers at the stronghold killed Burn, and the second one that Blister had hidden struck Clay, with no warning.
- Dragonbite vipers are rare, according to Starflight.
- The poison can be burned out of a dragons body, and provided that the wound is far away from the heart, the dragon's odds of surviving are fairly high. An example of this was when Clay was bitten on the leg and Peril used her firescales to save Clay.
- A dragonbite viper is the only known snake in Pyrrhia that can kill a dragon with one bite.
- Dragonbite vipers are mostly found in the Kingdom of Sand.
- They may live underground, the way most snakes do to avoid predators.