I was going on a travel to the lava cavern on mobile when I had to go on a long journey.After I finished I was going back to my base swimming in the water deep water to cross to the other side with my paracera when suddenly 4 cnidarias attacked him and I got off him he couldn't do anything,I just kept watching in shock thinking what to do so I decided to risk my life to save him I charged towards the cnidarias and attacked them with my primitive metal sword I got showed with electricity but I killed them at the end.My paracera was at half health,I don't know why at first place I got in water knowing there where cnidarias in there.