noun
whiptail gulper; gulper eel (family Saccopharyngidae)
Deep-sea fish known for its huge mouth and expandable stomach. Typically written in katakana.
深海にはフウセンウナギという奇妙な魚がいる。
In the deep sea, there is a strange fish called the whiptail gulper.
From 風船 (balloon) + 鰻 (eel), referring to its balloon-like expandable stomach.