Wild Boar of Northern Kingdoms (Elder Speech: Tirth) also known as the wild swine is quite dangerous natural (meaning he does not came with Conjunction) beast appearing in Northern Realms. The wild boar features prominently in the cultures of Islanders and Nordlings, many of which saw the animal as embodying warrior virtues.
Actual attacks on humans are rare, but can be serious, resulting in multiple penetrating injuries to the lower part of the body but its still animal not dangerous enough for witcher to be call, usually folks manage to hunt down the being, or pay crowns to hunter. Domesticated breed is called pig.
*To be added
Bestiary entry Edit
- How doth the little wild boar
Improve his shining tusks,
And rut them ‘gainst the forest floor,
And on the trees’ rough husks!
- How cheerfully he seems to grin
How neatly spreads his claws,
And welcomes little lasses in,
With gently smiling jaws!
Louis of Charolle, mathematician, author and poet
- These woodland beasts are as “wild” – untamed, nasty and aggressive – as their name indicates. To this day, many peasants in outlying Kaedweni villages believe wild boars persist on a diet of young maids, though in truth they most often slate their hunger with roots and acorns. Do not think this vegetarian diet makes them harmless, however. In fact, these animals’ stout build and sharp teeth render them veritable fur-covered combat machines. Mother Nature has additionally equipped them with dual pairs of tusks - upper "pipes" and lower "sabres" - and this weaponry's sum effect is to make the beasts the terrors of the woods, a threat to all who venture or dwell there, human, humanoid and otherwise. Boars also have hard, club-like snouts, which some peasants call their “whistles,” though no boar has ever been heard to make such a noise. Instead, they emit a characteristic grunt, which sounds to some like the snoring of an extremely overweight man. Another peasant belief claims boars have extremely prickly natures, and, if offended, will vent their anger by knocking down fences and gobbling up potatoes. Though they sometimes live alone, boars usually appear in small groups of 3 to 5 specimens.
Wild boar is also common symbol in coat of arms from Northern Kingdoms and maybe Empire of Nilfgaard also (athough there is not confirmed any).
A complete beast may represent what are seen as the positive qualities of the wild boar, namely courage and fierceness in battle; a boar's head may represent hospitality (from the custom of serving the boar's head in feasts), or it may symbolize that the bearer of the arms is a noted hunter. 
- Crach an Craite is called by Nilfgaardian soldiers Tirth ys Muire ("Sea Boar") for his deeds. Also when you pass around some islanders in Kaer Trolde harbor in The Witcher 3: Wild Hunt you can hear that three new ships prepared will bear names "Hemdall", "Kambi" and Crach´s private ship "Wild Boar of the Sea".