Essence
From Wormax Wiki
After each death a part of the gained worm's length is transformed into essence at the ratio 500 to 1. All authorized players can gain essence.
If after a battle, the worm's length is less than 500, the player will get no essence.
Essence is used for buying artifacts in the Shop.
Registered users can buy essence additionally by clicking on the button with an icon and the number of essence in the top left corner of the main menu.