How do you defeat Cakenstein on Free Realms

During Free Realms birthday, a chef named Glurga accidentally makes a monster made out of cake named Cakenstein. he appears in random places. Lets say he is in Seaside, you go there and then find him. (When he is in Seaside go to that octopus looking cafe and he will be nearby) There will be these fireworks called party fireworks and you will be able to use them to throw them at Cakenstein and he will be defeated, temporarily. After you defeat him you get a prize out of his treasure chest. Also, if you teleport to Sanctuary and go to the sign and follow the path in the way that would lead you out of Sanctuary and at somewhere on the path Cakenstein will be there and you can battle him. Only members can do it because he is a level 13 battle.