Twin(s) - derived from the Middle English word 'twinn' meaning "twofold". Cobra - short for the Portuguese 'cobra (de capello)' meaning "snake (with a hood)" derived from the Latin word 'colubra'. Mongoose - derived from an Indic language word (Marathi 'mangus' meaning "mongoose") Sedna - the Inuit goddess of the sea (I'm sorry but I can't find the etymology of this one.)I hope this helps:)