Identfy Feathery Slug

[whatcaneyedo]

You could also try doing a google image search for 'nudibranch', you many then be able to find one that looks like yours with a name attached. However even with a proper latin name most sources wont know much about them. In general they live less than one year and the majority of tanks dont have sufficient food for any of them. So they will actually just disapear and die somewhere long before old age gets them.