Capricorn

is usually depicted as a goat with a fish-tail, and I can sort of see how its source (parents

) would be mysterious... but that doesn't sound quite right.
Is it

? It's a STARfish, so Celeste would be a good name, even though it's a sea creature. You never exactly see where it comes from when it appears, and it stops being available after you complete the BoS quests. Actually, isn't it the one item in the game that is possible to "miss forever" if you don't unblock it during the quest? That sounds like limited edition.
Anyway, I guess that's my guess.
