1) Celtic mythology encompasses the folklore and legends of the Celtic peoples across Europe, particularly in regions like Ireland, Scotland, and Wales. It features deities like Morrigan, Cernunnos, and Brigid, and delves into themes of nature, magic, and the heroic exploits of legendary figures like Cu Chulainn.

2) Michael Jackson's album "Thriller" is the best-selling album of all time, with estimated sales of over 66 million copies worldwide.

3) The Triple Double in basketball refers to a player achieving double-digit totals in three of the following statistical categories: points, rebounds, assists, steals, or blocks.

4) The national animal of Australia is the kangaroo.