Bosses > Giant Troll
A giant beast with a lot of health (1500) and a big hammer which cannot be blocked entirely. If you get close it may stamp on you.
A thing to note is that although you can't block the hammer entirely, blocking it will reduce the damage it does significantly, so if its coming down on your head, then block. Also blocking means you have a quicker recovery allowing you to have a chance at a counter attack.
Timing is key here, after he has hammered, charge in with a counter. If he raises his hammer and you are close enough, try to get behind him and he will miss and take a long time doing it!
Jumping is also a way of avoiding some attacks if timed correctly.