Welcome to the Forum bejubot1500,
To do liver of the legends bring 3 cool drinks and as many sonic bombs as you can (Sonic bombs can be made from a screamer and gunpowder) leave the first area into the big open desert and you will see fins swimming in the sand, either hit these with a well timed sword a couple of times, or throw a flash bomb over the top of them. Kill this 'piscine' and carve it.
I didnt get 3 livers from 3 kills, i had to kill 6 so just keep going there not hard.