noun
tail and fins
Literal meaning: the tail and fins of a fish.
魚の尾ひれを切り落とす。
Cut off the tail and fins of the fish.
noun
Figurative use: adding made-up details to a story or rumor, making it more interesting or dramatic. Often used in the phrase 尾ひれが付く (to be embellished).
彼の話には尾ひれが付いている。
His story has been embellished.
噂に尾ひれが付いて広まった。
The rumor spread with exaggerations added.
Compound of 尾 (お, 'tail') and 鰭 (ひれ, 'fin'). The figurative sense comes from the idea of adding extra parts to a story, like adding fins to a tail.