The bestiary of the Witcher 3 is stuffed to the brim with so many weird wonders and creepy creatures, it's enough to make the Monster Hunter franchise throw down its oversized sword in submission.
And while CD Projekt RED focused heavily on the story aspect of these monsters; giving them intriguing questlines and sometimes heartbreaking backstories, some seem to exist solely to make Geralt severely rethink his career choices.
Not only that, a lot of these fights don't even take place during the main story, meaning that unless you obsessively visit every single notice board like a Sorceress on her child's PTA group, there's a good chance you've missed some of these challenging (and rewarding) bosses on your first playthrough.
Yet with the Witcher 3 recently celebrating its five year anniversary, there's never been a better time to blow the dust off those Samum bombs and jump into Geralt's leathery onesie once more. And armed with this list, you'll know all the best contracts, side quests and optional encounters to seek out when looking for the next trophy to slap on Roach.
Just make sure you pack your potions, yeah? You're certainly going to need them.
10. Niellen The Werewolf
While he may not be the most taxing creature on this list, Niellen is still a formidable foe, with the regenerative capabilities of a werewolf meaning you'll have to keep up the aggression in order to bring him down.
This is made all the harder by the fact that he can continually summon other wolves to aid him in battle, taking Geralt away from his main target. Plus he's just a big, talking dog at the end of the day. Who in their right mind would want to kill that?
As an added annoyance, Niellen's quest, Wild at Heart, is one of the more tragic to be found within the wilderness of Velen, filled with betrayal and deception and manipulation. By the time you reach the fight, Niellen is hard to kill simply because you won't want to.
Niellen's all about making hard choices, without any clear right or wrong path. Should you kill the beast or save the man? Is love really an excuse for evil? Is it better to whack him with the heavy attack or burn him with Igni? Heavy is the white haired head.