Lion's mane jellyfish are not often found in the North Sea. The jellyfish can sting badly with its long hairy tentacles located on the rim of the bell. These tentacles can grow up to several meters long! Those animals that are not sensitive to the poison prefer to live close by the jellyfish. The toxin scares away enemies, making it a safe place for others. Reddish specimen of blue jellyfish are sometimes mistaken for lion's mane jellyfish.