Monsterology: A Cat Is Fine Too

One of my sort-of-ancestors*, Charles II, was a cat person. More precisely, the man had a black cat (or, presumably, a series of black cats) which he carted around with him at all times as protection against witchcraft and general bad luck. As amusing as my coauthor finds this†, the relationship between cats and the supernatural has been a longstanding motif in Celtic myth.

 At the centre of this all is the cat-sìdhe (pronounced CAT-shee), which blurs the line between animal, human and faerie in a way that is not depicted for other shapeshifting supernatural creatures. They're described as large black cats, generally with green eyes and a white patch on their chest. Depending on who you ask, cat-sìdhe are either reincarnated witches, or their own brand of interspecies weirdness. I tend to lean towards the second one, since my mother's side of the family--who were at one point adopted by Clan MacIntosh-- believe that to be the explanation.

Clan MacIntosh, as it is, claims descent from a female cat-sìdhe. She was-- in her human form-- was the lover of the male MacIntosh clan founder and bore him several children. During a Viking attack on the clan homeland, she sacrificed her 9th and final life to defend her family. In her honour, the MacIntosh (and MacGillivray) family crest is a cat.

Bottom line, the intriguing thing about cat-sìdhe is that, unlike other shape-shifting faerie creatures which populate Celtic myth, they reputedly have soulsº. However, they usually operate with a typical feline disregard for human welfare, such as leading souls astray on their way to the afterlife, or banding together to form random extortionist cat-choirs. At the same time, there are enough stories that feature cat-sìdhe (such as the MacIntosh matriarch) who are willing to put themselves in harms way for their human companions (or at least deign to give them a helping hand), to make this sìdhe species less explicitly predatory-- and thus more complex and interesting to me-- than a lot of the other faeries.

Also, Clan MacIntosh kind of rocks.

*James V of Scotland believed in maintaining a work-life balance. With at least three of my female ancestors. Farther down the line, it becomes a bit more of a game of who's telling the truth about their sexcapades.
† [Actual gchat transcript] 
Coauthor: and we see how well that worked-- wait, which one was it again? 
Me: charles ii 
Coauthor: excuse me for a moment. I need to go buy a cat.
ºI've heard conflicting accounts on whether selkies have souls. If you have any insight/evidence/family stories/weird seal encounters, please share in the comments.