Cave Lion was a scrapped unique kitten that would have appeared on region 13 (this was also scrapped). It was going to ambush the player in a Secret Cave, and was the supposed "boss" of this region. It would have been very strong and may still appear in a future update (i highly doubt it)
This is the truth about Cave Lion, i don't know much, but i've tried my best :D*This entire section is fake. Someone's just really dedicated to spreading lies about a cat game for some reason.