I don’t know what caused it. He molted, and there it was.Yeah I'd be concerned. What caused that? How long has it been there?
Ok, thank you for the information.Hi
it looks like a cycst. Unfortunately there is nothing you can do apart from keeping an eye in it and monitor(limit) the food intake of your tarantula.Do not let her get too fat.
This can go either way.It may sort itself out with following moults or can get worse and burst.
Regards Konstantin