You will need the dlc pack: Lego Movie Aquaman Level Pack 2
Have King Shark unlocked from your original game 1000g completion.
You will first need to complete the level for the first time to unlock freeplay.Acheivement
Once you have done this load up the level again The Final Battle
Ensuring you select the character the King Shark
Play until you are on board the Sea Vessel and make sure you are the King Shark
defeat Orm’s Murk enemies then remove all Orm’s 6 hearts to complete the level.
All you require to pop the achievement is to land a confirmed hit on Orm with
, while you are king shark.
Then pop achievement unlocked.