Guild Wars 2

I attempted it with a few others for almost 15 minutes, evading and dodging a lot of times, all succesfull and still no achievement.

It appears to be bugged since the latest patch.

Got it within a minute. He suddenly did his fear thing, I was swimming out of there into the unknown because of it and got it. Otherwise dodge right after a stomp (wave)

I managed to get it. I do know that the first two attempts where it DID say evade, I did not get the achievement… but then I switched to the other (“north”) side of the tail, dodged, got 2 evade notices, and got the achievement.