You have to stop Mrbeast, Karl, Chris, Chandler, and the Mrbeast Lion (his logo), You can raid his studios and get money or clean the oceans to get some money, With the money you can buy a phone to spawn the boys, first, kill Karl, then Chris, Chandler, and then Mrbeast. After killing Mrbeast he drops a lost key you can open the lost chest with the lost key which spawns underwater then you get the Lost lion spawn egg, you can only spawn the lion in a forest.
