Snaptrapper

The Snaptrapper is a dragon that has four heads, each with three jaws. Their tail is forked like the Zippleback's and look and they look somewhat like the latter as well.The jaws open up in 3 different ways which resembles a flower blooming, and the spikes on their neck, body, and tail look similar to leaves. All four heads of the Snaptrapper have three tongues each. Their tongues resembles the anther and the pollen so that Snaptrapper could be mistaken as a flower.

It is 26 metres (84 feet) long.

How To Train Your Dragon (film)
The Snaptrapper first appeared in the film within the pages of the Dragon Manual when Hiccup was trying to find information on Night Furies. He did not state the dragon's name, although the book read that Snaptrappers are (extremely dangerous) (kill on sight).

In the Book of Dragons
In Book of Dragons short, they are categorized in the Fear class with the Hideous Zippleback. They attract prey with a sweet smell of chocolate, which emanates from all four mouths. Like all dragons, they shed their scales and talons, but these eventually regrow. Snaptrappers love rain and enjoy splashing in the mud which could be based off the fact flowers need water and damp areas.

Trivia

 * The Snaptrapper is based off a Venus Flytrap.
 * In the Book of Dragons special, the Snaptrapper is said to use the smell of chocolate to lure its prey; however, chocolate was unknown in Viking times, due to it being native to the Americas. It would have been more realistic to use honey, which was known to Vikings and more likely, since it is made from the nectar of flowers which the Snaptrapper's heads resemble. This might be a shoutout to the books though, due to one of the villains trying to find America.
 * It is unknown if the Snaptrapper can breathe fire.
 * The Snaptrapper has a possibility of shooting acid.
 * The Snaptrapper is one of the largest dragons, like the Scauldron, Timberjack, Typhoomerang, Boneknapper, Screaming Death and the Whispering Death.
 * It is most likely that the Snaptrappr can breathe fire because most dragons breathe fire or it might use gas like the Zippleback
 * The only Snaptrapper seen is green  so this could indicate that most Snaptrappers are green or greenish