lion's mane jellyfish
Refers specifically to the species Cyanea capillata, a large jellyfish found in cold northern waters.
I saw a lion's mane jellyfish in the sea off Hokkaido.
Katakana spelling is standard for this species name; usually written in kana.
Kanji spelling is rare and mainly used in specialized contexts; the word is usually written in kana.
Compound of 北 (kita, 'north') + 幽霊 (yūrei, 'ghost') + 水母 (kurage, 'jellyfish'), literally 'northern ghost jellyfish'. The name likely refers to its translucent, ghostly appearance and its habitat in northern seas.