After unloading the loot from at my estate in Solitude and practicing more smithing, I ventured into the Winking Skeever pub where a bunch of sailors were talking about great monsters in the Northern Sea. One of them, a sombre giant of a man named Captain Guomundr agreed to join me in hunting them. I even knew where to start, as I noticed new nearby islands when previously raiding the Thalmor Embassy.
A giant, talking, crab!
On the first isle we came across large mud crabs crawling along a ship wreck and one HUGE crustacean named Karkinos. The monster was very dangerous in melee so Guomundr and I switched to bows. It took a lot to penetrate the thick shell but with perseverance (and a lot of arrows) we finally killed it.
Nearby was a frozen iceberg full of frost atronarchs and "ice giants", who looked suspiciously exactly like frost atronarchs only twice the size. They made easy prey for sniping, but I couldn't shake the feeling I was being watched the whole time - even after slaying the last one. Then I saw it. The iceberg that wasn't an iceberg...
At least he's easy to hit!
Ymir, the Father of Ice Giants could easily pass for one of the smaller islands. At least that explained all the shipwrecks around him. Such a danger could not be allowed to live and so even more arrows were spent taking him down. Fortunately I think the sharks circling him actually prevented him from getting close, so he turned out to be an easy kill.