The HTTYD franchise puts a lot of attention onto the dragons (which duh, that should be expected it's called How To Train Your Dragon). However, in the world of HTTYD, the other less recognized animals that are not spectacular to our world, like the seagull and wolf, are still vital players in the ecosystem of the Barabric Archapelago. Today I would like to focus on the Wild Boar, and the anomaly of its precense in such a cold climate.
The Barbaric Archapelago is thought to be somewhere near or at the Arctic circle, above Scotland, west of Norway, east of Iceland. It is clearly shown throughout the franchise that (not counting RTTE their forests and climate look more appropriate for lower latitudes) the main biome is Boreal Taiga, with the presense of mostly coniferous trees as well as some deciduous trees. While summer is a brief reprieve from the cold, it can get so frigid that the sea ice can freeze over. I state this because it will become important later when discussing the Boar's natural range.
The Wild Boar is a very successful species of Sus(pig genus). They are ravenous omnivores and often live in groups together. They are very vocal and noisy with their friends and family. Being preyed on by animals from martens to tigers, it is likely dragons would feed on boars too. Despite this, they can be quite agressive and very dangerous in groups as they can gore and bite their enemies. Their hair and hides also give them deceptive amounts of protection from attacks, making them very hardy. The nose helps in foraging and gives the boar a great sense of smell. Being omnivores, they usually feed on tubers, roots, fungi, fruit, bark, fish, invertebrates, small animals, and carrion. It is shown that the HTTYD boars can be predators to even large creatures such as a weak Thunderdrum.
The presence of the wild boar this far north is odd, as to survive they need conditions that lack of regular snowfall. This is because snow greatly reduces their ability to forage. Yet somehow in the shows we see Boars in unforgiving landscapes like near glaciers. Boars in our world could not survive such polar conditions, lest they starve. This indicates that the HTTYD boars are unique and are doing something different to survive.
My theory is that the HTYYD boar is a unique species, different from the common wild boar. They are more agressive then usually to survive attacks from dragons, as well as to facilitate a more predatory nature. When a lack of plant or fungi is available, I could imagine that they would hunt in mobs to attack sick and fallen dragons, as well as scavenge their dead remains. Since dragons seem to be fairly plentiful, this could help contribute a portion of their diet. HTTYD boars are shown to have an even greater sense of smell that can tract blood. Fur would be longer and thicker to help keep in warmth during cold winters. Tusks are notably larger then their mainland counterparts, which also would help in self protection and predation. Despite how hardy and competetive the HTTYD boar is, it still would be preyed upon by humans, wolves, and dragons such as the Changewing. Domestication is not present in the wild boar and is seen as a food item and pest to vikings, as well as pets and wrestling partners(cough cough Ruffnut and Tuffnut!).
Due to their niche, boars would probably have great competition with the Speed Stinger, as they are both gregarious and scrounge and scavenge for various food. A form of nice partitioning can be examined, as Speed Stingers tend to rely on their coordination, speed, and defensive stinger to steal and gather food, whereas the HTTYD boar is more agressive and blunt and ravenous, yet are slower and less organized and relies on its sense of smell more than its eyes.
To end this, how's this for a scientific name for the HTTYD boar: Sus barbarus, meaning Barbaric pig!