Venomous Vorpent

The Venomous Vorpent is a very small dragon with a poison sting on the end of its tail. The venom inside its sting causes the sickness Vorpentitis.

In The Books
In How To Speak Dragonese, Alvin The Treacherous had slipped a Venomous Vorpent inside Hiccup's How To Speak Dragonese book as a trap. This, however, was before Hiccup became a "god" and hovered in the air. Alvin attempted to remove the dragon before he gave the half of the book back to Hiccup, but Hiccup snatched it from him too quickly. At one point on the hot-air balloon ride out of Fort Sinister, Fishlegs was stung by the Venomous Vorpent. The dragon drops out of the story at this point, though it does appear(as an illustration, with words written around it) in the epilogue, stating "I don't like happy endings. They are too neat, too nice. I like a little spice in my stories," implying that one of the three had been stung by it.

In The Film Adaptation
The Venomous Vorpent does not appear in the film.