These guys spawn in the 4 listed caves (lower and upper south, central and swamp caves)
My advise is play with sound (they have a characteristic hissing sound) and if you see one shot it full of arrows or poke it with a spear/pike take stimulants/stimberries if you get bitten to starve of the torpor increase
They are already wrong! It should say something more like:
"Found everywhere but the dark caves of the island, this creature will gladly ruin your day by jumping out and killing you as soon as you even think about going to the swamp. Nearly impossible to tame because it has to be tamed via passive which is very difficult to do. Worst of all you need to feed them fertilized eggs. Why can't it e a little easier?