What made you want to look up xenial? Please tell us where you read or heard it (including the quote, if possible).
Black dog is an oft-used phrase to mean depression. Here's a link that attributes the phrase to Winston Churchill, but I suspect he didn't invent it. I like the way they described it though: Black Dog was Churchill's name for his depression, and as is true with all metaphors, it speaks volumes.
Fu Lion Dogs. 1,046 pages on this wiki. Fu Lions or Fu Dogs, traditionally known in Chinese simply as Shi (Chinese: ç; pinyin: shÄ«; literally lion), and often called Foo Dogs in the West, are a common representation of the lion in pre-modern China.,046 pages on this wiki. Fu Lions or Fu Dogs, traditionally known in Chinese simply as Shi (Chinese: ç; pinyin: shÄ«; literally lion), and often called Foo Dogs in the West, are a common representation of the lion in pre-modern China.